The Second
Wo ld Ocean
Assessmen
WORLD OCEAN ASSESSMENT II
Volume II
The Second
Wo ld Ocean
Assessmen
WORLD OCEAN ASSESSMENT II
Volume II
Co e pho o: Yung-Sen Wu
Uni ed Na ions Wo ld Oceans Day Pho o Compe i ion
Uni ed Na ions publica ion
Sales no.: E.21.V.5
ISBN: 978-92-1-1-130422-0
eISBN: 978-92-1-1-604006-2
Copy igh © Uni ed Na ions, 2021
All igh s ese ed
P in ed a he Uni ed Na ions, New Yo k
Ŵŵŵŵiii
Con en s
Volume I
Page
Fo ewo d by he Sec e a y-Gene al ............................................. iii
Summa y .................................................................
P e ace ................................................................. ii
Pa one: Summa y ........................................................... 1
Chap e 1: O e all summa y.................................................... 3
Keyno e poin s ..................................................... 5
1. In oduc ion..................................................... 5
2. D i e s ......................................................... 6
3. Cleaning up he ocean............................................ 7
4. P o ec ing ma ine ecosys ems..................................... 10
5. Unde s anding o he ocean o sus ainable managemen ............. 13
6. P omo ing sa e y om he ocean .................................. 15
7. Sus ainable ood om he ocean................................... 16
8. Sus ainable economic use o he ocean............................. 19
9. E ec i e implemen a ion o in e na ional law as eƽec ed in
he Uni ed Na ions Con en ion on he Law o he Sea ................. 21
Pa wo: In oduc ion......................................................... 37
Chap e 2: App oach o he assessmen ......................................... 39
Keyno e poin s ..................................................... 41
1. Pu pose o he second Wo ld Ocean Assessmen ..................... 41
2. P ima y audience and amewo k o he second Wo ld Ocean Assessmen 42
3. P epa a ion o he second Wo ld Ocean Assessmen .................. 43
4. Te minology .................................................... 44
5. Acknowledgemen s.............................................. 45
Re e ences......................................................... 45
Chap e : Scien iƼc unde s andinK o ɸ he ocean.................................. 47
Keyno e poin s ..................................................... 49
1. In oduc ion..................................................... 49
2. Desc ip ion o changes in da a, echnology and models since he
Ƽ s Wo ld Ocean Assessmen and hei consequences o o e all
unde s anding, including socioeconomic consequences............... 50
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Wo ld Ocean Assessmen II:ŴVolume II
Page
3. Key egion-speciƼc changes and consequences...................... 51
4. Ou look o scien iƼc unde s anding o he ocean..................... 56
5. Key emaining knowledge gaps .................................... 56
6. Key emaining capaci y-building gaps............................... 57
Re e ences......................................................... 58
Pa h ee: ( i e s o chanKes in heɸma ine en i onmen .......................... 63
Chap e 4: D i e s ............................................................ 65
Keyno e poin s ..................................................... 67
1. In oduc ion..................................................... 67
2. D i e s o change in he ma ine en i onmen ......................... 69
3. Key egion-speciƼc issues o aspec s associa ed wi h d i e s .......... 73
4. Ou look ........................................................ 74
5. Key emaining knowledge and capaci y-building gaps................. 76
Re e ences......................................................... 77
Pa ou : Cu en s a e o he ma ine en i onmen andɸi s ends ................... 81
Chap e : 8 ends in he physical and chemical s a e o ɸ he ocean................... 83
Keyno e poin s ..................................................... 85
1. In oduc ion..................................................... 85
2. Physical and chemical s a e o he ocean............................ 87
3. Knowledge gaps................................................. 100
4. Summa y....................................................... 101
Re e ences......................................................... 103
Chap e : 8 ends in he biodi e si y o ɸ heɸmain a a o ma ine bio a ................ 111
In oduc ion........................................................ 113
Chap e 6A: Plank on phy oplank on, ^ooplank on, mic obes andɸ i uses......... 115
Keyno e poin s ..................................................... 117
1. In oduc ion..................................................... 117
2. Summa y o chap e 6 o he Ƽ s Wo ld Ocean Assessmen ........... 118
3. Regions a ge ed in he p esen Wo ld Ocean Assessmen ............. 119
4. Es ima ing plank on di e si y ..................................... 120
5. Mic obial plank on . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
6. Me azoan zooplank on ........................................... 124
7. Documen ed ends.............................................. 125
8. Ou look ........................................................ 128
Re e ences......................................................... 130

Ŵŵŵŵ
Con en s
Chap e 6B: Ma ine in e eb a es ............................................ 141
Keyno e poin s ..................................................... 143
1. In oduc ion..................................................... 143
2. Summa y o he si ua ion eco ded in he Ƽ s Wo ld Ocean Assessmen . 143
3. Desc ip ion o en i onmen al changes 2010Ɓ2020................... 144
4. In e na ional and go e nmen al esponses .......................... 151
5. Achie emen o ele an Sus ainable De elopmen Goals and con ibu ion
o Aichi Biodi e si y Ta ge 11 ..................................... 153
6. Key emaining knowledge gaps and capaci y-building gaps ............ 153
Re e ences......................................................... 154
Addendum by he G oup o Expe s o he Regula P ocess o Global
Repo ing and Assessmen o he S a e o he Ma ine En i onmen ,
including Socioeconomic Aspec s.................................. 158
Re e ences......................................................... 159
Chap e 6C: Fishes ........................................................ 161
Keyno e poin s ..................................................... 163
1. In oduc ion..................................................... 163
2. Documen ed change in he s a e o Ƽsh biodi e si y . . . . . . . . . . . . . . . . . . 165
3. Consequences o biodi e si y change on human communi ies,
economies andɸwell-being ........................................ 168
4. Key egion-speciƼc changes and consequences...................... 169
5. Ou look ........................................................ 171
Re e ences......................................................... 172
Chap e 6D: Ma ine mammals............................................... 177
Keyno e poin s ..................................................... 179
1. In oduc ion..................................................... 179
2. Ce aceans...................................................... 181
3. Pinnipeds....................................................... 184
4. Si enians ....................................................... 186
5. O e s and pola bea ............................................. 186
6. Consequences o changes on human communi ies, economies
andɸwell-being................................................... 187
7. Ou look ........................................................ 188
8. Key emaining knowledge gaps .................................... 189
9. Key emaining capaci y-building gaps............................... 189
Re e ences......................................................... 190
Page
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Wo ld Ocean Assessmen II:ŴVolume II
Chap e 6E: Ma ine ep iles ................................................. 195
Keyno e poin s ..................................................... 197
1. In oduc ion..................................................... 197
2. Conse a ion s a us o ma ine ep iles.............................. 197
3. Regional ends.................................................. 199
4. Th ea s......................................................... 201
5. Economic and social consequences o he changes o ma ine ep ile
popula ions..................................................... 203
6. Key knowledge and capaci y-building gaps .......................... 204
Re e ences......................................................... 205
Chap e 6F: Seabi ds....................................................... 211
Keyno e poin s ..................................................... 213
1. In oduc ion..................................................... 213
2. Desc ip ion o en i onmen al changes be ween 2010 and 2020......... 214
3. Consequences o changes in seabi d popula ions on human
communi ies, economies andɸwell-being ............................ 217
4. Ou look ........................................................ 218
5. Key emaining knowledge gaps .................................... 219
6. Key emaining capaci y-building gaps............................... 220
Re e ences......................................................... 220
Chap e 6G: Ma ine plan s and mac oalgae.................................... 225
Keyno e poin s ..................................................... 227
1. In oduc ion..................................................... 227
2. Mang o es ..................................................... 227
3. Sal ma sh plan s................................................ 229
4. Seag asses ..................................................... 230
5. Mac oalgae..................................................... 232
6. Consequences o changes on human communi ies, economies
andɸwell-being................................................... 240
7. Key emaining knowledge and capaci y-building gaps................. 241
8. Ou look ........................................................ 241
Re e ences......................................................... 242
Chap e 7: T ends in he s a e o biodi e si y in ma ine habi a s..................... 251
In oduc ionɸ ....................................................... 253
Chap e 7A: In e idal zone.................................................. 255
Keyno e poin s ..................................................... 257
1. In oduc ion..................................................... 257
2. Desc ip ion o he en i onmen al changes be ween 2010 and 2020...... 260
Page
Ŵŵŵŵ ii
Con en s
3. Economic and social consequences................................ 261
4. Key egion-speciƼc changes and consequences...................... 261
5. Ou look ........................................................ 262
6. Key emaining knowledge gaps .................................... 263
7. Key emaining capaci y-building gaps............................... 263
Re e ences......................................................... 264
Chap e 7B: Biogenic ee s and sandy, muddy and ocky sho e subs a es ......... 267
Keyno e poin s ..................................................... 269
1. In oduc ion..................................................... 269
2. Documen ed change in s a e o biogenic ee s and sandy, muddy
and ocky sho e subs a es ....................................... 272
3. Consequences o he changes on human communi ies, economies
andɸwell-being................................................... 275
4. Key egion-speciƼc changes and consequences...................... 277
5. Ou look ........................................................ 279
6. Key emaining knowledge and capaci y-building gaps................. 280
Re e ences......................................................... 281
Chap e 7C: A oll and island lagoons ......................................... 289
Keyno e poin s ..................................................... 291
1. In oduc ion..................................................... 291
2. Documen ed changes in s a e o a olls and island lagoons............. 292
3. Consequences o he changes on human communi ies, economies
andɸwell-being................................................... 295
4. Key egion-speciƼc changes and consequences ..................... 296
5. Ou look ........................................................ 296
6. Key emaining knowledge gaps .................................... 297
7. Key emaining capaci y-building gaps............................... 298
Re e ences......................................................... 299
Chap e 7D: T opical and sub opical co alɸ ee s ............................... 305
Keyno e poin s ..................................................... 307
1. In oduc ion..................................................... 307
2. Desc ip ion o en i onmen al changes be ween 2010 and 2020......... 308
3. Desc ip ion o economic and social consequences and/o o he
economic o social changes ...................................... 309
4. Key egion-speciƼc changes and consequences...................... 310
5. Ou look ........................................................ 312
6. Key emaining knowledge gaps .................................... 313
7. Key emaining capaci y-building gaps............................... 313
Re e ences......................................................... 314
Page
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Wo ld Ocean Assessmen II:ŴVolume II
Page
Chap e 7E: Cold wa e co als ............................................... 321
Keyno e poin s ..................................................... 323
1. In oduc ion and summa y o he Ƽ s Wo ld Ocean Assessmen ........ 323
2. Desc ip ion o en i onmen al changes be ween 2010 and 2020......... 324
3. Economic and social consequences................................ 329
4. Key egion-speciƼc changes and consequences...................... 330
5. Ou look ........................................................ 330
6. Key emaining knowledge gaps .................................... 331
7. Key emaining capaci y-building gaps............................... 332
Re e ences......................................................... 333
Chap e 7F: Es ua ies andɸdel as............................................. 339
Keyno e poin s ..................................................... 341
1. In oduc ion..................................................... 341
2. Documen ed changes in he s a e o es ua ies and del as.............. 342
3. Consequences o he changes o human communi ies, economies
andɸwell-being................................................... 344
4. Key egion-speciƼc changes and consequences...................... 345
5. Ou look ........................................................ 346
6. Key emaining knowledge and capaci y-building gaps................. 347
Re e ences......................................................... 348
Chap e 7G: Seag ass meadows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
Keyno e poin s ..................................................... 355
1. In oduc ion..................................................... 355
2. Socioeconomic consequences .................................... 356
3. Region-speciƼc changes.......................................... 357
4. Ou look ........................................................ 358
5. Key emaining knowledge gaps .................................... 358
6. Key emaining capaci y-building gaps............................... 359
Re e ences ........................................................ 362
Chap e 7H: Mang o es .................................................... 365
Keyno e poin s ..................................................... 367
1. In oduc ion..................................................... 367
2. Documen ed change in s a e o mang o es be ween 2010 and 2020 .... 368
3. Consequences o he changes o human communi ies, economies
andɸwell-being................................................... 370
4. Key egion-speciƼc changes and consequences...................... 372
5. Ou look ........................................................ 373
6. Key emaining knowledge and capaci y-building gaps................. 373
Re e ences......................................................... 374
Ŵŵŵŵx
Con en s
Page
2. O sho e hyd oca bon explo a ion, p oduc ion and decommissioning . . . 285
3. Economic, social, and en i onmen al aspec s o o sho e hyd oca bon
explo a ion, p oduc ion and decommissioning ....................... 288
4. Key knowledge and capaci y-building gaps .......................... 290
5. Role o he o sho e hyd oca bon indus y in acili a ing he ma ine
enewable ene gy indus y ........................................ 291
6. Conclusion ..................................................... 292
Re e ences ........................................................ 293
Chap e 2: T ends in inpu s o an h opoKenic noise in o he ma ine en i onmen ..... 297
Keyno e poin s ..................................................... 299
1. In oduc ion..................................................... 299
2. Desc ip ion o he en i onmen al s a us............................. 300
3. Desc ip ion o economic and social consequences and o he economic
o social changes ............................................... 308
4. Key egion-speciƼc changes and consequences...................... 308
5. Ou look ........................................................ 310
6. Key emaining knowledge gaps .................................... 312
7. Key emaining capaci y-building gaps............................... 313
Re e ences ........................................................ 313
Chap e 21: De elopmen s in enewable ene Ky sou ces ........................... 321
Keyno e poin s ..................................................... 323
1. In oduc ion..................................................... 323
2. S a e o ma ine enewable ene gy a he global le el .................. 324
3. Po en ial en i onmen al impac s o ma ine enewable ene gy
de elopmen ................................................... 329
4. Socioeconomic beneƼ s and impac s om ma ine enewable ene gy
deploymen ..................................................... 332
5. Key emaining knowledge and capaci y-building gaps................. 333
6. An icipa ed u u e ends.......................................... 335
Re e ences......................................................... 336
Chap e 22: In asi e species ................................................... 343
Keyno e poin s ..................................................... 345
1. In oduc ion .................................................... 345
2. Documen ed baseline and changes in non-indigenous species ......... 347
3. Consequences o human communi ies, economies andɸwell-being ..... 348
4. Key egion-speciƼc baselines, changes and consequences............. 350
5. Ou look ........................................................ 354
6. O he .......................................................... 356
Re e ences......................................................... 356

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Wo ld Ocean Assessmen II:ŴVolume II
Page
Chap e 2: De elopmen s in he e plo a ion o and use o ma ine Kene ic esou ces . 363
Keyno e poin s ..................................................... 365
1. In oduc ion..................................................... 365
2. T ends be ween 2010 and 2020.................................... 366
3. Economic and social consequences and changes .................... 370
4. Key egion-speciƼc de elopmen s in knowledge and hei consequences 371
5. Capaci y-building gaps ........................................... 371
6. Me hodological challenges and u u e ends ........................ 373
7. Ma ine gene ic esou ces and he Sus ainable De elopmen Goals...... 374
Re e ences......................................................... 376
Chap e 24: 1a ine hyd a esɸƁ a po en ially eme KinK issue ........................ 381
Keyno e poin s ..................................................... 383
1. In oduc ion..................................................... 383
2. Wha a e ma ine hyd a es? ........................................ 383
3. Po en ial isks om ma ine me hane hyd a es ....................... 386
4. Ma ine hyd a es as a sou ce o ene gy.............................. 388
5. Key knowledge and capaci y-building gaps .......................... 390
6. Ou look ........................................................ 390
Re e ences......................................................... 390
Chap e 25: Cumula i e e ec s................................................. 395
Keyno e poin s ..................................................... 397
1. In oduc ion..................................................... 397
2. Cumula i e e ec s assessmen s................................... 398
3. Regional applica ions o cumula i e e ec s assessmen s on
he ma ine en i onmen : dis ibu ion and app oaches ................. 402
4. Ou look ........................................................ 406
Re e ences......................................................... 413
Pa si : T ends in manaKemen app oaches o he ma ine en i onmen ............. 421
Chap e 2: De elopmen s in ma ine spa ial planninK.............................. 423
Keyno e poin s ..................................................... 425
1. In oduc ion..................................................... 425
2. Types o ma ine spa ial planning ................................... 426
3. Ma ine spa ial planning: a s ep-by-s ep app oach owa d
ecosys em-based managemen .................................... 427
4. Tools o ma ine spa ial planning................................... 428
5. P og ess in implemen ing ma ine spa ial planning .................... 430
Re e ences......................................................... 436
Ŵŵŵŵx ii
Con en s
Page
Chap e 27: De elopmen s in manaKemen app oaches............................ 441
Keyno e poin s ..................................................... 443
1. In oduc ion..................................................... 443
2. Managemen app oaches......................................... 444
3. Ad ances in ocean managemen app oaches........................ 448
4. Managemen ools o suppo mi iga ion o and adap a ion o clima e
change, including building esilience................................ 458
5. Key egion-speciƼc issues ........................................ 460
6. Capaci y-building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461
7. Gaps and u u e pe spec i es...................................... 462
8. Ou look ........................................................ 463
Re e ences......................................................... 465
Chap e 28: De elopmen sɸin he unde s andinK o o e all beneƼ s
om he ocean o humans ..................................................... 471
Keyno e poin s ..................................................... 473
1. In oduc ion..................................................... 473
2. BeneƼ s and hei dis ibu ion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
3. DisbeneƼ s o humans............................................ 478
4. Th ea s o ocean ecosys em se ices............................... 479
5. Sa egua ding ocean beneƼ s h ough egional and in e na ional
coope a ion and imp o ed implemen a ion o in e na ional law as
eƽec ed in he Uni ed Na ions Con en ion on he Law o he Sea ....... 480
Re e ences......................................................... 483
Anne es ................................................................. 487
Anne I: O iKinal membe s o he w i inK eams app o ed by he &u eau ............. 489
Anne II: Pee e iewe s nomina ed o each chap e .............................. 497
55
Chap e 9
P essu es om
changes in
clima e and
a mosphe e
Con ibu o s: 'EVPSW+EVGME7SXSPIEHQIQFIVERHGSRZIRIV(IRMWI&VIMXFYVK1SRMGE'EQTMP-
PSW4EXVMGME'EWXMPPS-&VMGIRS7EREI'LMFEGS-PIEHQIQFIV1EXXLI['SPPMRW+ERM )WRESPE
/EVIR)ZERWGS-PIEHQIQFIV0SYMWI&*MVXL8LSQEW*VʯPMGLIV.EWSR1,EPP-7TIRGIV(EZMH
Halpe n, Ka en L. Hun e , Gab iel Iba a, Sung-Yong Kim, Roxy M. Koll, Ka hleen McInnes, Jon
Saen^, 'a 8hanh :u co-leaH membe , &ess ;a H anH 8ymon >ielinsOi co-leaH membe .
Ŵŵŵŵ57
Chap e 9: P essu es om changes in clima e and a mosphe e
Keyno e poin s
xEx eme clima e e en s. Ma ine hea -
wa es and opical cyclones a e shown o
be inc easing in se e i y owing o human
ac i i ies and a e ha ing an impac on na-
u e and human socie ies. Ex eme El Niño
e en s ha e been obse ed bu , because
hey occu in eUuen ly, a human inƽuence
has no been de ec ed. All h ee phenome-
na a e p ojec ed o inc ease in he u u e,
wi h he se e i y o impac s also inc eas-
ing, bu such inc eases can be educed by
clima e change mi iga ion e o s.
xSea le el ise. The ala ming obse ed pace
o sea le el ise, combined wi h inc easing
s o miness and coas al u baniza ion, has
esul ed in he ampliƼed suscep ibili y o
coas al ci ies o e osion and ƽooding and
inc eased he need o subs an ial in es -
men s in ha d in as uc u e and he es o-
a ion o na u al ba ie s, such as ee s.
x3cean aciHiƼca ion anH Heox]Kena ion.
The accele a ed inc ease o an h opogenic
CO2 in he a mosphe e is c ea ing an in-
c ease in he acidiƼca ion and deoxygen-
a ion o he ocean. Unde such condi ions,
bo h in na u e and in he labo a o y, ma ine
o ganisms ha suppo ecosys ems and
human li elihoods and nu i ion ypically
espond poo ly. Ma ine habi a s expe i-
ence a loss o di e si y, many long-li ed
o ganisms die and a ew esilien spe-
cies p oli e a e. Less se ious damage o
li e-suppo ing ecosys ems would be pos-
sible unde lowe -emission scena ios.
x3 Le TL]sical anH cLemical T oTe ies.
Changes in ocean empe a u e and salin-
i y induced by clima e change and human
ac i i ies a e a ec ing ma ine ecosys ems
by changing he dis ibu ion o ma ine spe-
cies, dec easing he ecological alue o
coas al ecosys ems and changing ma ine
p ima y p oduc ion. Human well-being and
he economy a e consequen ly a ec ed.
1. In oduc ion
The Ƽ s pa o he p esen chap e is based
on h ee opics in he con ex o ex eme
clima e e en s ela ed o he ocean, namely,
ma ine hea wa es, ex eme El Niño Sou he n
Oscilla ion e en s and opical cyclones. Bo h
physical aspec s o he impac o clima e
change on he phenomena and po en ial im-
pac s on na u al and human sys ems a e con-
side ed. The conclusions a e based on a much
mo e de ailed assessmen ha can be ound
in chap e 6 o he Special Repo on Oceans
and C yosphe e in a Changing Clima e o he
In e go e nmen al Panel on Clima e Change
29.
An ex eme e en is one ha is a e a a pa -
icula place and ime o yea . (eƼni ions o
“ a e” a y, bu an ex eme e en is no mally
as a e as, o a e han, he en h o nine ie h
pe cen ile o a p obabili y es ima ed om ob-
se a ions. By deƼni ion, he cha ac e is ics o
wha is called an ex eme e en may a y om
place o place in an absolu e sense. When a
pa e n o ex eme wea he pe sis s o some
ime, such as a season, i may be classed as
an ex eme clima e e en , especially i i yields
an a e age o o al ha is i sel ex eme (e.g.,
high empe a u e, d ough o o al ain all o e
a season.
The second pa o he chap e expands upon
p essu es om changes in ocean physical and
chemical p ope ies. P ojec ed sea empe a-
u e inc eases o up o 1.5°C o e p e-indus ial
le els by 2050 will con inue o d i e la i udinal
abundance shi s in ma ine species, including

58ŵŵŵ
Wo ld Ocean Assessmen II:Ŵ:olume II
hose o impo ance o coas al li elihoods.
Many la ge coas al ci ies a e loca ed in del aic
se ings and a e ulne able o ƽoods because
o hei p oximi y o i e s and he sea, gene al
low ele a ions and land subsidence (Nicholls
and o he s, 200.
Ca bon dioxide emissions and global wa ming
a e also causing ocean acidiƼca ion and deox-
ygena ion. Those changes ha e consequences
o he people who depend on heal hy ma ine
ecosys ems wo ldwide. A he ime o he Ƽ s
Wo ld Ocean Assessmen (Uni ed Na ions,
201, he chemis y o ocean acidiƼca ion
was well unde s ood, ye he consequences o
ecosys ems and socie y we e poo ly known.
The e ec s o declining oxygen on nu ien cy-
cles and Ƽsh s ocks we e p edic ed o wo sen,
especially when clima e change-d i en oxygen
deple ion combines wi h coas al eu ophica-
ion. Reduced biodi e si y and declines in Ƽsh
popula ions we e linked o alling oxygen le els
ac oss he wo ldƅs oceans. New in o ma ion is
p o ided on ma ine o ganism and ecosys em
esponses o ocean acidiƼca ion and deoxy-
gena ion and ela ed capaci y-building.
In he p esen chap e , in conjunc ion wi h
chap e 5, he clima e change aspec s o
he p esen Assessmen a e de eloped. The
p esen chap e expands on he p essu es on
ma ine ecosys ems and human popula ions
o some o he physical and chemical chang-
es caused by clima e change. Some ela ed
aspec s a e also co e ed in chap e 7K and
chap e 15.
2. Clima e p essu es: ex eme clima e e en s and p essu es
om changes in ocean physical and chemical p ope ies
2.1. Ex eme clima e e en s
Ma ine hea wa es a e pe iods o ex emely
high ocean empe a u es ha pe sis o days
o mon hs, ha can ex end up o housands o
km and can pene a e mul iple hund eds o m
in o he deep ocean (Hobday and o he s, 2016.
O e he pas wo decades, ma ine hea wa es
ha e had a nega i e impac on ma ine o gan-
isms and ecosys ems in all ocean basins,
including c i ical ounda ion species such as
co als, seag asses and kelps (Hughes and
o he s, 201 Smale and o he s, 2019. Sa el-
li e obse a ions e eal ha ma ine hea wa es
doubled in equency be ween 1982 and 2016,
and ha hey ha e also become longe las ing
and mo e in ense and ex ensi e (F öliche and
o he s, 2018 Oli e and o he s, 2018. Be ween
2006 and 2015, 8 o 90ɸpe ɸcen o all globally
occu ing ma ine hea wa es we e a ibu able
o he empe a u e inc ease since he pe iod
1850Ɓ1900 (F öliche and o he s, 2018.
Ma ine hea wa es will u he inc ease in e-
quency, du a ion, spa ial ex en and in ensi y
unde u u e global wa ming (F öliche and
o he s, 2018 (a ma aki and o he s, 2019,
pushing some ma ine o ganisms, Ƽsh s ocks
and ecosys ems beyond he limi s o hei
esilience, wi h cascading impac s on econo-
mies and socie ies (Smale and o he s, 2019.
Globally, he equency o ma ine hea wa es
is e y likely o inc ease by a ac o o abou
50 imes by he pe iod 2081–2100 unde he
high-emission Rep esen a i e Concen a ion
Pa hway (RCP 8.5 scena io and by a ac o o
abou 20 imes unde he low-emission RCP
2.6 scena io (:an :uu en and o he s, 2011, el-
a i e o he e e ence pe iod 1850–1900. Such
u u e ends in ma ine hea wa e equency
can la gely be explained by inc eases in mean
ocean empe a u e. The la ges changes in he
equency o ma ine hea wa es a e p ojec ed
o he A c ic Ocean and he opical oceans
(Ƽgu e I In e go e nmen al Panel on Clima e
Change (IPCC, 2019, chap. 6, Ƽgu e 6..
59
Chap e 9: P essu es om changes in clima e and a mosphe e
Figu e I
0SGEXMSRWSJI XVIQIIZIRXW[MXLERMHIRXMƼIHPMROXSGPMQEXIGLERKIGEYWIHF]LYQER
ac i i ies
Cyclone Ex eme ain all D ough Ma ine hea wa e Tidal ƽooding Wa e-induced
ƽooding
Cold o snows o m
Compound e en :
d ough ,
low sea le els
Compound e en :
d ough , ain all,
MHW
Compound e en :
mul iple cyclones
Sea-ice minimum
Sou ce:Figu eɸadap ed om IPCC, 2019, Ƽgu e 6.2.
Limi ing global wa ming would educe he isk
o impac s o ma ine hea wa es, bu c i ical
h esholds o some ecosys ems (e.g., kelp
o es sandco al ee swill be eached e en
a ela i ely low le els o u u e global wa m-
ing(Kingando he s,2017.Ea lywa ning
sys ems, p oducing skil ul o ecas s o ma ine
hea wa es, can u he help o educe ulne -
abili ies in Ƽshing, ou ism and conse a ion,
bu a e ye unp o en on a la ge scale (Payne
and o he s, 2017Tommasi and o he s, 2017.
One o he bes da a- ich examples o he im-
pac o a ma ine hea wa e on well-managed
Ƽshe iesiso heGul o Alaskain heNo h
PaciƼc. A p olonged wa m ocean e en weak-
ened ben hic ocean and su ace mixing, in u n
dis up ing ophies, in e eb a e and o age
Ƽsh popula ions, and decima ed he PaciƼccod
Ƽshe y, igge ing a se ies o epea ing mass
ma ine mammal and seabi d die-o s ha had
a ipple e ec h ough coas al economies.
The El Niño Sou he n Oscilla ion is a coupled
a mosphe e-ocean phenomenon, iden iƼed by
an oscilla ion be ween wa m and cold ocean
empe a u es in he opical cen al eas e n
PaciƼcOceanandanassocia edƽuc ua ion in
he global-scale opical and sub opical su -
ace p essu e pa e ns. Typically, i has a p e-
e ed imescale o abou wo o se en yea s.
I is o en measu ed by he su ace p essu e
anomaly di e ence be ween Tahi i, F ench Pol-
ynesia, and Da win, Aus alia, and/o he sea
su ace empe a u es in he cen al and eas -
e n equa o ial PaciƼc(RasmussenandCa pen-
e , 1982.I hasclima ice ec s h oughou
he PaciƼc egionandinmanyo he pa so
60ŵŵŵ
Wo ld Ocean Assessmen II:Ŵ:olume II
he wo ld h ough global eleconnec ions. The
wa m phase o he Oscilla ion is called El Niño
and he cold phase is called La Niña.
The s onges El Niño and La Niña e en s since
he p e-indus ialɸe a ha e occu ed du ing he
pas 50 yea s, and ha a iabili y is unusually
high when compa ed wi h a e age a iabili y
du ing he las millennium (Cobb and o he s,
201 San oso and o he s, 2017. The e ha e
been h ee occu ences o ex eme El Niño
e en s du ing he mode n obse a ional pe i-
od (1982/8, 1997/98, 2015/16, all cha ac e -
ized by p onounced ain all in he no mally d y
equa o ial Eas PaciƼc. The e ha e been wo
occu ences o ex eme La Niña (1988/89,
1998/99.ɸ
Ex eme El Niño and La Niña e en s a e likely
o occu mo e equen ly wi h global wa ming
and a e likely o in ensi y exis ing impac s, wi h
d ie o we e esponses in se e al egions
ac oss he globe, e en a ela i ely low le els
o u u e global wa ming (Cai and o he s, 2014;
Cai and o he s, 2015; Powe and Delage, 2018.
Sus ained long- e m moni o ing and imp o ed
o ecas s can be used in managing he isks o
ex eme El Niño and La Niña e en s associa ed
wi h human heal h, ag icul u e, Ƽshe ies, co al
ee s, aquacul u e, wildƼ e, d ough and ƽood
managemen (LƅHeu eux and o he s, 2017.
A opical cyclone is he gene al e m o
a s ong, cyclonic-scale dis u bance ha
o igina es o e he opical ocean. Based on
one-minu e maximum sus ained wind speed,
he cyclonic dis u bances a e ca ego ized
in o opical dep essions (Ƶ 17 m/s, opical
s o ms (18–2 m/s and opical cyclones
(ƶɸ m/s, ca ego y 1 o ca ego y 5 (Knu son
and o he s, 2010. A opical cyclone is called
a hu icane, yphoon o cyclone, depending on
geog aphic loca ion.
An h opogenic clima e change has inc eased
p ecipi a ion, winds and ex eme sea le el
e en s associa ed wi h a numbe o obse ed
opical cyclones. Fo example, s udies ha e
shown ha he ain all in ensi y o opical cy-
clone (Hu icane Ha ey inc eased by a leas
8ɸpe ɸcen (8–19ɸpe ɸcen  owing o clima e
change (Risse and Wehne , 2017; Van Olden-
bo gh and o he s, 2017. An h opogenic clima e
change may ha e con ibu ed o a polewa d mi-
g a ion o maximum opical cyclone in ensi y
in he wes e n No h PaciƼc in ecen decades
ela ed o an h opogenically o ced opical
expansion (Sha mila and Walsh, 2018. The e
is eme ging e idence o a numbe o egional
changes in opical cyclone beha iou , such
as an inc ease in he annual global p opo ion
o ca ego y 4 o 5 opical cyclones in ecen
decades, ex emely se e e opical cyclones
occu ing in he A abian Sea, cyclones making
land all in Eas and Sou h-Eas Asia, an in-
c ease in equency o mode a ely la ge s o m
su ge e en s in he Uni ed S a es since 1923
and a dec ease in equency o se e e opical
cyclones making land all in eas e n Aus alia
since he la e 1800s. The e is low conƼdence
ha hey ep esen de ec able an h opogenic
signals. Ex eme wa e heigh s, which con ib-
u e o ex eme sea le el e en s, coas al e osion
and ƽooding, ha e inc eased in he Sou he n
Ocean and he No h A lan ic Ocean by abou
1.0 cm pe yea and 0.8 cm pe yea o e he
pe iod 1985–2018 (Young and Ribal, 2019.
An inc ease in he a e age in ensi y o opical
cyclones, and he associa ed a e age p ecipi a-
ion a es, is p ojec ed o a 2°C global empe -
a u e ise, al hough he e isɸlow conƼdenceɸin
u u e equency changes a he global scale
(Yamada and o he s, 2017. Rising sea le els
will con ibu e o highe ex eme sea le els
associa ed wi h opical cyclones in he u u e
(Ga ne and o he s, 2017.ɸP ojec ions sugges
ha he p opo ion o ca ego y 4 and 5 opical
cyclones will inc ease (Knu son and o he s,
2015; Pa k and o he s, 2017.ɸSuch changes
will a ec s o m su ge equency and in ensi y,
as well as coas al in as uc u e and mo ali y.
In es men in disas e isk educ ion, ƽood
managemen (ecosys em and enginee ed
and ea ly wa ning sys ems dec eases
Ŵŵŵŵ61
Chap e 9: P essu es om changes in clima e and a mosphe e
economic loss om opical cyclones ha
occu nea coas s and islands. Howe e , such
in es men s may be hinde ed by limi ed local
capaci ies (e.g., ageing in as uc u e and
o he non-clima ic ac o s ha , o example,
can lead o inc eased losses and mo ali y
om ex eme winds and s o m su ges in de-
eloping coun ies despi e adap a ion e o s.
The e is eme ging e idence o inc easing
isks o loca ions a ec ed by unp eceden ed
s o m ajec o ies. Managemen o isk om
such changing s o m ajec o ies and in ensi y
p o es challenging because o he diƾcul ies
o ea ly wa ning and i s ecep i i y by a ec ed
popula ions.
2.2. Sea le el ise and ci ies
Ci ies loca ed along coas lines and in a chipe-
lagic and island S a es a e becoming inc eas-
ingly suscep ible o e osion and sea le el ise
(De She binin and o he s, 2007; Hanson and
o he s, 2011; Takagi and o he s, 2016. Many
comp ise la ge a eas o eclaimed land ( he
gain o land om he sea, we lands o o he
wa e bodies, which is e ained and p o ec ed
om e osion by ha d enginee ed s uc u es,
such as sea walls and ock a mou ing (Sen-
gup a and o he s, 2018. I is likely ha many
o such enginee ed coas lines will need o be
adap ed and upg aded o keep pace wi h ising
sea le els. In highly u banized en i onmen s
ha a e o en al eady hea ily deg aded, ha d
enginee ed s uc u es a e o en he only op ion
a ailable and a e conside ed o be success ul
op ions (Hallega e and o he s, 2013; Hinkel
and o he s, 2014, bu he e a e a wide ange o
b oade nega i e impac s o land eclama ion
and hose s uc u es on he su ounding en i-
onmen (Da o n and o he s, 2015. Globally,
many egions (especially ci ies a e claiming
ha mo e han 50ɸpe ɸcen o hei coas lines
a e a mou ed (e.g., Chapman, 2003; Bu and
o he s, 2013, and ha numbe will likely ise
in he u u e in esponse o bu geoning econ-
omies, coas al popula ions and u baniza ion
(e.g., see plans o he eclama ion o he en-
i e coas lines o wo Malaysian s a es in Chee
and o he s, 2017.
As an al e na i e o ha d enginee ed coas al
de ences, cons uc ion o which is complex
and expensi e, whe e possible, na u al coas -
al ecosys ems such as mang o es and sal
ma shes should be used as na u al ba ie s
o combined wi h ha d in as uc u e using
hyb id app oaches (Temme man and o he s,
2013. The use o such ecosys ems can no
only p o ec he land bu also p o ide aluable
ecosys em unc ions and se ices. As ha d
enginee ed coas al de ences may be consid-
e ed an e ec i e sho - e m solu ion o coas -
al ƽooding, mo e in es men will be needed
owing o obse ed inc easing s o miness
and sea le el ise (Mendelsohn and o he s,
2012; Vi ousek and o he s, 2017. By 2010, he
global a e age sea le el was calcula ed o be
52.4ɸmm abo e he 1993 le el and, by 2018, i
had isen o 89.9 mm abo e he 1993 le el (Na-
ional Oceanic and A mosphe ic Adminis a-
ion (NOAA, 2019. The a e o change is also
inc easing. Fo he pe iod 1993–2018, he a e
o inc ease was calcula ed a 3.2 mm pe yea ,
while o he pe iod 2010–2018, i was calcu-
la ed o be much as e , a 4.7 mm pe yea . De-
spi e signiƼcan unce ain ies emaining, he
In e go e nmen al Panel on Clima e Change
p edic s ha sea le el ise will con inue o
cen u ies, e en i mi iga ion measu es a e pu
in place. The po en ial widesp ead collapse o
ice shel es could lead o a la ge wen y-Ƽ s
cen u y sea le el ise o up o se e al en hs
o a me e (Chu ch and o he s, 2013, which
will ha e d as ic consequences o coas al, a -
chipelagic and small island ci ies, in pa icula
hose in low-lying a eas.
U baniza ion could, howe e , also p o ide op-
po uni ies o isk educ ion, gi en ha ci ies
a e engines o economic g ow h and cen es o
inno a ion, poli ical a en ion and p i a e sec o
in es men s (Ga schagen and Rome o-Lankao,
2015. Hallega e and o he s (2013 conduc ed
a global analysis o p esen and u u e losses
68ŵŵŵ
Wo ld Ocean Assessmen II:ŴVolume II
e ec i e measu es o mi iga e he impac s o
ocean acidiƼca ion and deoxygena ion, which
may, as a esul , ha e less se ious consequences
o he millions o people who a e dependen on
coas al p o ec ion, Ƽshe ies and aquacul u e in
lowe -emission scena ios.
4. Summa y
Ma ine hea wa es a e shown o be inc easing
in equency and in ensi y owing o clima e
change caused by human ac i i ies and a e
ha ing a mos ly nega i e impac on ma ine
ecosys ems. Ma ine hea wa es and hei im-
pac s a e p ojec ed o inc ease in he u u e
bu hose inc eases can be s ongly limi ed by
e o s o mi iga e clima e change. Fo ecas -
ing sys ems may be employed in adap ing o
he e ec s o ma ine hea wa es.
Ex eme El Niño and La Niña e en s ha e been
obse ed bu , because hey occu in equen -
ly, a human inƽuence has no been de ec ed.
Ne e heless, models indica e an inc ease in
he equency o bo h phases o he oscilla ion
unde u u e scena ios o global wa ming. As
in he case o ma ine hea wa es, o ecas ing
sys ems, which al eady exis , may be em-
ployed in isk managemen and adap a ion.
While changes in he equency and spa ial dis-
ibu ion o opical cyclones a e ha d o de ec
in he obse a ional eco d, s udies o indi id-
ual cyclones ha e shown a human inƽuence
on hei in ensi y, in pa icula , he associa ed
ain all. Changes in in ensi y a e p ojec ed o
inc ease in he u u e, wi h associa ed impac s
on s o m su ges and coas al in as uc u e.
Al hough all coas al ci ies a e al eady acing
ising sea le els, low-lying ci ies and de elop-
ing coun ies ha lack he abili y o in es in
coas al de ence measu es and na u al ba ie
es o a ion will su e damage and losses o
a highe deg ee. Global popula ion s udies
sugges ha people a e eloca ing o coas -
al a eas and will con inue o do so, he eby
pu ing mo e people a isk economically and
socially. Al hough ci ies a e ypically cen es
o inno a ion and in es men , key examples
demons a e he diƾcul y in sol ing such
complex p oblems in ulne able loca ions.
Damage and losses a e also d i en by exis ing
ulne abili ies in coas al in as uc u e and
may no be solely a ibu ed o ising sea le -
els. Ra he , inc easing sea le els may exace -
ba e exis ing issues, inc easing isk.
The complex in e ac ions o empe a u e and
salini y wi h nu ien s and chemical cycles o
he ocean imply ha a ia ions in hose a ia-
bles owing o clima e change and an h opo-
genic impac hus a ec ma ine ecosys ems,
popula ion, coas al communi ies and he
ela ed economy. Ocean wa ming is causing
signiƼcan damage o ma ine ecosys ems, and
species a e losing hei habi a s, o cing hem
o adap o eloca e o new empe a u es o look
o new eeding, spawning o nu se y a eas.
Ocean acidi y and he a ailabili y o suƾcien
oxygen bo h unde pin he p o ision o ma ine
ecosys em se ices o human socie y. Rapid
changes in ocean acidi y and alling oxygen
le els caused by clima e change and an h opo-
genic CO2ɸemissions a e, howe e , now being
obse ed, which is changing ma ine habi a s
and ecosys ems wo ldwide. Wa ming is caus-
ing oxygen le els o all, and acidiƼca ion is
apidly changing he ca bona e chemis y
o su ace ocean wa e s, which oge he a e
educing he g ow h and su i al o many o -
ganisms and deg ading ecosys em esilience.
Closing knowledge gaps in ocean science
by suppo ing capaci y-building e o s ha
inc ease he unde s anding o how he ocean
and i s ecosys ems a e esponding o changes
in ocean physical and chemical p ope ies is
an impo an pa hway o educing he impac s
o such changes and achie ing Sus ainable
De elopmen Goal 14.

Ŵŵŵŵ69
Chap e 9: P essu es om changes in clima e and a mosphe e
Re e ences
In oduc ion
In e go e nmen al Panel on Clima e Change (IPCC (2019. IPCC Special Repo on he Ocean and C y-
osphe e in a Changing Clima e.
Nicholls, R.J., and o he s (2008. Ranking Po Ci ies wi h High Exposu e and Vulne abili y o Clima e
Ex emes, No. 1. h ps://doi.o g/10.1787/011766488208.
Uni ed Na ions (2017. The Fi s Global In eg a ed Ma ine Assessmen : Wo ld Ocean Assessmen I. Cam-
b idge: Camb idge Uni e si y P ess.
Ex eme clima e e en s
Cai, Wenju, and o he s (2014. Inc easing equency o ex eme El Niño e en s due o g eenhouse wa m-
ing. Na u e Clima e Change, ol.ɸ4, No. 2, p. 111.
Cai, Wenju, and o he s (2015. Inc eased equency o ex eme La Niña e en s unde g eenhouse wa m-
ing. Na u e Clima e Change, ol.ɸ5, No. 2, p. 132.
Cobb, Kim M., and o he s (2013. Highly a iable El Niño – sou he n oscilla ion h oughou he Holocene.
Science, ol.ɸ339, No. 6115, pp.ɸ67–70.
Da ma aki, SoƼa, and o he s (2019. Fu u e e olu ion o Ma ine Hea wa es in he Medi e anean Sea.
Clima e Dynamics, pp. 1–22.
F öliche , Thomas L., and o he s (2018. Ma ine hea wa es unde global wa ming. Na u e, ol.ɸ560,
No.ɸ7718, p. 360.
Ga ne , And a J., and o he s (2017. Impac o clima e change on New Yo k Ci yƅs coas al ƽood haza d:
Inc easing ƽood heigh s om he p eindus ial o 2300 CE. P oceedings o he Na ional Academy
o Sciences, ol.ɸ114, No. 45, pp.ɸ11861–11866.
Hobday, Alis ai J., and o he s (2016. A hie a chical app oach o deƼning ma ine hea wa es. P og ess in
Oceanog aphy, ol.ɸ141, pp.ɸ227–238.
Hughes, Te y P., and o he s (2018. Global wa ming ans o ms co al ee assemblages. Na u e, ol.ɸ556,
No. 7702, p. 492.
In e go e nmen al Panel on Clima e Change (IPCC (2018. Global Wa ming o 1.5°C. An IPCC Special
Repo on he Impac s o Global Wa ming o 1.5°C abo e P e-Indus ial Le els and Rela ed Global
G eenhouse Gas Emission Pa hways, in he Con ex o S eng hening he Global Response o he
Th ea o Clima e Change, Sus ainable De elopmen , and E o s o E adica e Po e y. Valé ie Mas-
son-Delmo e and o he s, eds.
CCCCCCCCCC (2019. IPCC Special Repo on he Ocean and C yosphe e in a Changing Clima e.
King, And ew D., and o he s (2017. Aus alian clima e ex emes a 1.5°C and 2°C o global wa ming. Na-
u e Clima e Change, ol.ɸ7, No. 6, p. 412.
Knu son, Thomas R., and o he s (2010. T opical cyclones and clima e change. Na u e Geoscience, ol.ɸ3,
No. 3, pp.ɸ157–163.
Knu son, Thomas R., and o he s (2015. Global p ojec ions o in ense opical cyclone ac i i y o he la e
wen y-Ƽ s cen u y om dynamical downscaling o CMIP5/RCP4. 5 scena ios. Jou nal o Clima e,
ol.ɸ28, No. 18, pp.ɸ7203–7224.
LƅHeu eux, Michelle L., and o he s (2017. Obse ing and p edic ing he 2015/16 El Niño. Bulle in o he
Ame ican Me eo ological Socie y, ol.ɸ98, No. 7, pp.ɸ1363–1382.
70ŵŵŵ
Wo ld Ocean Assessmen II:ŴVolume II
Oli e , E ic C.J., and o he s (2018. Longe and mo e equen ma ine hea wa es o e he pas cen u y.
Na u e Communica ions, ol.ɸ9, No. 1, a . 1324.
Pa k, Doo-Sun R., and o he s (2017. Asymme ic esponse o opical cyclone ac i i y o global wa ming
o e he No h A lan ic and wes e n No h PaciƼc om CMIP5 model p ojec ions. Scien iƼc Re-
po s, ol.ɸ7, a . 41354.
Payne, Ma k R., and o he s (2017. Lessons om he Ƽ s gene a ion o ma ine ecological o ecas p od-
uc s. F on ie s in Ma ine Science, ol.ɸ4, a . 289.
Powe , Sco B., and F anʡois P.D. Delage (2018. El Niño – sou he n oscilla ion and associa ed clima ic
condi ions a ound he wo ld du ing he la e hal o he wen y-Ƽ s cen u y. Jou nal o Clima e,
ol.ɸ31, No. 15, pp.ɸ6189–6207.
Rasmussen, E.M. and T.H. Ca pen e (1982. Va ia ions in opical sea su ace empe a u e and su ace
wind Ƽelds associa ed wi h he Sou he n Oscilla ion/El Niño.ɸMon hly Wea he Re iew, ol.ɸ110,
No.ɸ5, pp. 354–384.
Risse , Ma k D., and Michael F. Wehne (2017. A ibu able human-induced changes in he likelihood and
magni ude o he obse ed ex eme p ecipi a ion du ing hu icane Ha ey. Geophysical Resea ch
Le e s, ol.ɸ44, No. 24, pp.ɸ12–457.
San oso, Agus, and o he s (2017. The deƼning cha ac e is ics o ENSO ex emes and he s ong 2015/
2016 El Niño. Re iews o Geophysics, ol.ɸ55, No. 4, pp.ɸ1079–1129.
Sha mila, S., and K.J.E. Walsh (2018. Recen polewa d shi o opical cyclone o ma ion linked o Hadley
cell expansion. Na u e Clima e Change, ol.ɸ8, No. 8, p. 730.
Smale, Dan A., and o he s (2019. Ma ine hea wa es h ea en global biodi e si y and he p o ision o eco-
sys em se ices. Na u e Clima e Change, ol.ɸ9, No. 4, p. 306.
Tommasi, Desi ee, and o he s (2017. Managing li ing ma ine esou ces in a dynamic en i onmen : he
ole o seasonal o decadal clima e o ecas s. P og ess in Oceanog aphy, ol.ɸ152, pp.ɸ15–49.
Van Oldenbo gh, G.J., and o he s (2017. A ibu ion o ex eme ain all om Hu icane Ha ey, Augus
2017. En i onmen Resea ch Le e s, ol.ɸ12, No. 12, 124009, h p://doi.o g/10.1088/1748-9326/
aa9e 2.
Vuu en, De le P., and o he s (2011. The ep esen a i e concen a ion pa hways: an o e iew. Clima ic
Change, ol.ɸ109, No. 1, a . 5. h ps://doi.o g/10.1007/s10584-011-0148-z.
Yamada, Yohei, and o he s (2017. Response o opical cyclone ac i i y and s uc u e o global wa ming in
a high- esolu ion global nonhyd os a ic model. Jou nal o Clima e, ol.ɸ30, No. 23, pp.ɸ9703–9724.
Young, Ian R., and Agus inus Ribal (2019. Mul ipla o m e alua ion o global ends in wind speed and
wa e heigh . Science, ol.ɸ364, No. 6440, pp.ɸ548–552.
Sea le el ise and ci ies
Bu , John A., and o he s (2013. U ban b eakwa e s as ee Ƽsh habi a in he Pe sian Gul . Ma ine Pollu-
ion Bulle in, ol.ɸ72, No. 2, pp.ɸ342–350.
C40 Ci ies (2019. www.c40.o g/o he / he- u u e-we-don- -wan -s aying-aƽoa - he-u ban- esponse- o-
sea-le el- ise.
Chapman, M.G. (2003. Pauci y o mobile species on cons uc ed seawalls: e ec s o u baniza ion on
biodi e si y. Ma ine Ecology P og ess Se ies, ol.ɸ264, pp.ɸ21–29.
Chee, Su Yin, and o he s (2017. Land eclama ion and a iƼcial islands: walking he igh ope be ween
de elopmen and conse a ion. Global Ecology and Conse a ion, ol.ɸ12, pp.ɸ80–95.
Chu ch, J.A., and o he s (2013. Sea le el change. In Clima e Change 2013: The Physical Science Basis.
Con ibu ion o Wo king G oup I o he Fi h Assessmen Repo o he In e go e nmen al Panel on
Ŵŵŵŵ71
Chap e 9: P essu es om changes in clima e and a mosphe e
Clima e Change, T.F. S ocke , and o he s, eds., pp.ɸ1137–1216. Camb idge, New Yo k: Camb idge
Uni e si y P ess.
Da o n, Ka he ine A., and o he s (2015. Ma ine u baniza ion: an ecological amewo k o designing mul-
i unc ional a iƼcial s uc u es. F on ie s in Ecology and he En i onmen , ol.ɸ13, No. 2, pp.ɸ82–90.
De She binin, Alex, and o he s (2007. The ulne abili y o global ci ies o clima e haza ds. En i onmen
and U baniza ion, ol.ɸ19, No. 1, pp.ɸ39–64.
Ga schagen, Ma hias, and Pa icia Rome o-Lankao (2015. Explo ing he ela ionships be ween u baniza-
ion ends and clima e change ulne abili y. Clima ic Change, ol.ɸ133, No. 1, pp.ɸ37–52.
Hallega e, S ephane, and o he s (2013. Fu u e ƽood losses in majo coas al ci ies. Na u e Clima e Change,
ol.ɸ3, No. 9, p. 802.
Hanson, Susan, and o he s (2011. A global anking o po ci ies wi h high exposu e o clima e ex emes.
Clima ic Change, ol.ɸ104, No. 1, pp.ɸ89–111.
Hinkel, Jochen, and o he s (2014. Coas al ƽood damage and adap a ion cos s unde 21s cen u y sea-le -
el ise. P oceedings o he Na ional Academy o Sciences, ol.ɸ111, No. 9, pp.ɸ3292–3297.
Jonke s, L., and o he s (2019. Global change d i es mode n plank on communi ies away om he p e-in-
dus ial s a e. Na u e, 570, pp. 372–375. h ps://doi.o g/10.1038/s41586-019-1230-3.
Mendelsohn, Robe , and o he s (2012. The impac o clima e change on global opical cyclone damage.
Na u e Clima e Change, ol.ɸ2, No. 3, p. 205.
Na ional Oceanic and A mosphe ic Adminis a ion (NOAA (2019. Sea Le el Rise Viewe . 2019. h ps://
coas .noaa.go /digi alcoas / ools/sl .h ml.
Sengup a, Dh i i aj, and o he s (2018. Building beyond land: An o e iew o coas al land eclama ion in 16
global megaci ies. Applied Geog aphy, ol.ɸ90, pp.ɸ229–238.
Takagi, Hi oshi, and o he s (2016. P ojec ion o coas al ƽoods in 2050 Jaka a. U ban Clima e, ol.ɸ17,
pp.ɸ135–145.
Temme man, S ijn, and o he s (2013. Ecosys em-based coas al de ence in he ace o global change.
Na u e, ol.ɸ504 (7478, pp.ɸ79–83.
Vi ousek, Sean, and o he s (2017. Doubling o coas al ƽooding equency wi hin decades due o sea-le el
ise. Scien iƼc Repo s, ol.ɸ7, No. 1, a . 1399.
P essu es om changes in empe a u e
Ba ange, M., and o he s (2018. Impac s o clima e change on Ƽshe ies and aquacul u e: FAO Fishe ies
and Aquacul u e Technical Pape No. 627. Rome, FAO.
Blancha d, Julia L., and o he s (2017. Linked sus ainabili y challenges and ade-o s among Ƽshe ies,
aquacul u e and ag icul u e. Na u e Ecology & E olu ion, ol.ɸ1, No. 9, p. 1240.
Boyd, P.W., and o he s (2016. Physiological esponses o a Sou he n Ocean dia om o complex u u e
ocean condi ions. Na u e Clima e Change, ol.ɸ6, No. 2, p. 207.
Cocha d, Roland, and o he s (2008. The 2004 sunami in Aceh and Sou he n Thailand: a e iew on coas al
ecosys ems, wa e haza ds and ulne abili y. Pe spec i es in Plan Ecology, E olu ion and Sys em-
a ics, ol.ɸ10, No. 1, pp.ɸ3–40.
Food and Ag icul u e O ganiza ion o he Uni ed Na ions (FAO (2018. Deep Ocean S ewa dship Ini ia i e.
Deep-Ocean Clima e Change Impac s on Habi a , Fish and Fishe ies. Technical Pape 638. Rome.
Fu, Weiwei, and o he s (2016. Clima e change impac s on ne p ima y p oduc ion (NPP and expo p oduc-
ion (EP egula ed by inc easing s a iƼca ion and phy oplank on communi y s uc u e in he CMIP5
models. Biogeosciences, ol.ɸ13, No. 18, pp.ɸ5151–70. h ps://doi.o g/10.5194/bg-13-5151-2016.
Golden, Ch is ophe D., and o he s (2016. Nu i ion: Fall in Ƽsh ca ch h ea ens human heal h. Na u e
News, ol.ɸ534, No. 7607, p. 317.
72ŵŵŵ
Wo ld Ocean Assessmen II:ŴVolume II
Hilmi, Na halie, and o he s (2014. Exposu e o Medi e anean coun ies o ocean acidiƼca ion. Wa e ,
ol.ɸ6, No. 6, pp.ɸ1719–1744.
In e go e nmen al Panel on Clima e Change (IPCC (2018. Global Wa ming o 1.5°C. An IPCC Special
Repo on he Impac s o Global Wa ming o 1.5°C abo e P e-Indus ial Le els and Rela ed Global
G eenhouse Gas Emission Pa hways, in he Con ex o S eng hening he Global Response o he
Th ea o Clima e Change, Sus ainable De elopmen , and E o s o E adica e Po e y. Valé ie Mas-
son-Delmo e and o he s, eds.
Pendle on, Linwood H., and o he s (2016. Has he alue o global ma ine and coas al ecosys em se ices
changed? Ma ine Policy, ol.ɸ64, pp.ɸ156–158.
Semenza, Jan C., and o he s (2017. En i onmen al sui abili y o Vib io in ec ions in a wa ming clima e: an
ea ly wa ning sys em. En i onmen al Heal h Pe spec i es, ol.ɸ125, No. 10, a . 107004.
Swee man, And ew K., and o he s (2017. Majo impac s o clima e change on deep-sea ben hic ecosys-
ems. Elemen a: Science o he An h opocene, ol.ɸ5, No. 4.
Wo m, Bo is, and o he s (2006. Impac s o biodi e si y loss on ocean ecosys em se ices. Science,
ol.ɸ314, No. 5800, pp.ɸ787–790.
Yool, And ew, and o he s (2017. Big in he ben hos: Fu u e change o seaƽoo communi y biomass in a
global, body size- esol ed model. Global Change Biology, ol.ɸ23, No. 9, pp.ɸ3554–3566.
P essu es om changes in ocean chemis y
Agos ini, Syl ain, and o he s (2018. Ocean acidiƼca ion d i es communi y shi s owa ds simpliƼed
non-calciƼed habi a s in a sub opical- empe a e ansi ion zone. Scien iƼc Repo s, ol.ɸ8, No. 1,
a . 11354.
Alb igh , Rebecca, and o he s (2018. Ca bon dioxide addi ion o co al ee wa e s supp esses ne commu-
ni y calciƼca ion. Na u e, ol.ɸ555, No. 7697, p. 516.
Ba aglia, Gianna, and Fo una Joos (2018. Ma ine N2O emissions om ni iƼca ion and deni iƼca ion
cons ained by mode n obse a ions and p ojec ed in mul imillennial global wa ming simula ions.
Global Biogeochemical Cycles, ol.ɸ32, No. 1, pp.ɸ92–121.
B ei bu g, Denise L., and o he s (2009. Hypoxia, ni ogen, and Ƽshe ies: in eg a ing e ec s ac oss local
and global landscapes. Annual Re iew o Ma ine Science, ol.ɸ1, pp.ɸ329–349.
B ei bu g, Denise L., and o he s (2018. Declining oxygen in he global ocean and coas al wa e s. Science,
ol.ɸ359, No.6371, eaam7240.
B ei bu g, Denise L., and o he s (2019. Mul iple s esso s – o ces ha combine o wo sen deoxygena ion
and i s e ec s. In Ocean Deoxygena ion: E e yone’s P oblem Causes, Impac s, Consequences and
Solu ions. Lo ely, D., and Bax e , J. eds. IUCN, pp.ɸ225–247.
B odie, Julie , and o he s (2014. The u u e o he no heas A lan ic ben hic ƽo a in a high CO2 wo ld.
Ecology and E olu ion, ol.ɸ4, No. 13, pp.ɸ2787–2798.
Bui enhuis, E ik T., and o he s (2018. Cons ain s on global oceanic emissions o N2O om obse a ions
and models. Biogeosciences, ol.ɸ15, No. 7, pp.ɸ2161–2175.
Cayabyab, R.R., and o he s (2002. His amine Fish Poisoning Following Massi e Fishkill in Bolinao, Pan-
gasinan, Feb ua y 2002. Regional Epidemiology and Su eillance Uni I Repo 3. Philippines:
Depa men o Heal h.
Connell, Sean D., and o he s (2018. The duali y o ocean acidiƼca ion as a esou ce and a s esso . Ecolo-
gy, ol.ɸ99, No. 5, pp.ɸ1005–1010.
Cooley, Sa ah R., and o he s (2016. Communi y-le el ac ions ha can add ess ocean acidiƼca ion. F on-
ie s in Ma ine Science, ol.ɸ2, a . 128.
Ŵŵŵŵ73
Chap e 9: P essu es om changes in clima e and a mosphe e
Co nwall, Ch is ophe E., and o he s (2017. Ino ganic ca bon physiology unde pins mac oalgal esponses
o ele a ed CO2. Scien iƼc Repo s, ol.ɸ7, a . 46297.
C aig, J. Ke in (2012. Agg ega ion on he edge: e ec s o hypoxia a oidance on he spa ial dis ibu ion o
b own sh imp and deme sal Ƽshes in he No he n Gul o Mexico. Ma ine Ecology P og ess Se ies,
ol.ɸ445, pp.ɸ75–95.
Dam, Hans G., and Hannes Baumann (2017. Clima e change, zooplank on and Ƽshe ies. Clima e Change
Impac s on Fishe ies and Aquacul u e: A Global Analysis, ol.ɸ2, pp.ɸ851–874.
Deu sch, Cu is, and o he s (2015. Clima e change igh ens a me abolic cons ain on ma ine habi a s.
Science, ol.ɸ348, No. 6239, pp.ɸ1132–1135.
Diaz, Robe J., and Ru ge Rosenbe g (2008. Sp eading dead zones and consequences o ma ine eco-
sys ems. Science, ol.ɸ321, No. 5891, pp.ɸ926–929.
Eks om, Julia A., and o he s (2015. Vulne abili y and adap a ion o US shellƼshe ies o ocean acidiƼca-
ion. Na u e Clima e Change, ol.ɸ5, No. 3, p. 207.
Enochs, I.C., and o he s (2015. Shi om co al o mac oalgae dominance on a olcanically acidiƼed ee .
Na u e Clima e Change, ol.ɸ5, No. 12, p. 1083.
Foo, Shawna And ea, and o he s (2018. The ca bon dioxide en s o Ischia, I aly, a na u al sys em o
assess impac s o ocean acidiƼca ion on ma ine ecosys ems: an o e iew o esea ch and com-
pa isons wi h o he en sys ems. In Oceanog aphy and Ma ine Biology, pp.ɸ237–310. CRC P ess.
F oehlich, Halley E., and o he s (2017. When does hypoxia a ec managemen pe o mance o a Ƽshe y?
A managemen s a egy e alua ion o Dungeness c ab (Me aca cinus magis e  Ƽshe ies in Hood
Canal, Washing on, Uni ed S a es. Canadian Jou nal o Fishe ies and Aqua ic Sciences, ol.ɸ74, No.
6, pp.ɸ922–932.
Gallo, Na alya D., and o he s (2019. Home swee suboxic home: ema kable hypoxia ole ance in wo
deme sal Ƽsh species in he Gul o Cali o nia. Ecology, ol.ɸ100, No. 3, e02539.
Gallo, N.D., and L.A. Le in (2016. Fish ecology and e olu ion in he wo ldƅs oxygen minimum zones and
implica ions o ocean deoxygena ion. In Ad ances in Ma ine Biology, ol. 74, pp. 117–198. Else ie .
Global Ocean AcidiƼca ion Obse ing Ne wo k (GOA-ON (2019. Global Ocean AcidiƼca ion Obse ing
Ne wo k (GOA-ON) Implemen a ion S a egy. www.goa-on.o g.
Gʬmez, Ca los E., and o he s (2018. G ow h and eeding o deep-sea co al Lophelia pe usa om he
Cali o nia ma gin unde simula ed ocean acidiƼca ion condi ions. Pee J, ol.ɸ6, e5671.
Hall-Spence , Jason M., and Ben P. Ha ey (2019. Ocean acidiƼca ion impac s on coas al ecosys em
se ices due o habi a deg ada ion. Eme ging Topics in Li e Sciences, ol.ɸ3, No. 2, pp.ɸ197–206.
Hall-Spence , Jason M., and Ro Allen (2015. The impac o CO2 emissions on “nuisance” ma ine species.
Resea ch and Repo s in Biodi e si y S udies, ol.ɸ4, pp.ɸ33–46.
He n o h, Bodil E., and Susanne P. Baden (2018. Al e a ion o hos -pa hogen in e ac ions in he wake o cli-
ma e change – Inc easing isk o shellƼsh associa ed in ec ions?ɸEn i onmen al Resea ch,ɸ ol.ɸ61,
pp.ɸ425–438.
In e go e nmen al Panel on Clima e Change (IPCC (2019. IPCC Special Repo on he Ocean and C y-
osphe e in a Changing Clima e.
Keis e , Julie E., and Lo en B. Tu le (2013. E ec s o bo om-laye hypoxia on spa ial dis ibu ions and com-
muni y s uc u e o mesozooplank on in a sub-es ua y o Puge Sound, Washing on, U.S.A. Lim-
nology and Oceanog aphy, ol.ɸ58, No. 2, pp.ɸ667–80. h ps://doi.o g/10.4319/lo.2013.58.2.0667.
Koslow, J. An hony, and o he s (2011. Impac o declining in e media e-wa e oxygen on deepwa e Ƽshes
in he Cali o nia Cu en . Ma ine Ecology P og ess Se ies, ol.ɸ436, pp.ɸ207–218.

74ŵŵŵ
Wo ld Ocean Assessmen II:ŴVolume II
Koslow, J. An hony, and o he s (2018. The e ol ing esponse o mesopelagic Ƽshes o declining midwa e
oxygen concen a ions in he sou he n and cen al Cali o nia Cu en . ICES Jou nal o Ma ine Sci-
ence, ol.ɸ76, No. 3, pp.ɸ626–638.
Lam, Vicky W.Y., and o he s (2019. Dealing wi h he e ec s o ocean acidiƼca ion on co al ee s in he
Indian Ocean and Asia. Regional S udies in Ma ine Science, ol.ɸ28, 100560.
Lina es, C is ina, and o he s (2015. Pe sis en na u al acidiƼca ion d i es majo dis ibu ion shi s in
ma ine ben hic ecosys ems. P oceedings o he Royal Socie y B: Biological Sciences, ol.ɸ282,
No.ɸ1818, 20150587.
McCo mick, Lillian R., and Lisa A. Le in (2017. Physiological and ecological implica ions o ocean de-
oxygena ion o ision in ma ine o ganisms. Philosophical T ansac ions o he Royal Socie y A:
Ma hema ical, Physical and Enginee ing Sciences, ol.ɸ375, No. 2102, 20160322.
Munday, Philip L. (2017. New pe spec i es in ocean acidiƼca ion esea ch: edi o ƅs in oduc ion o he
special ea u e on ocean acidiƼca ion. Biology Le e s, ol.ɸ13.
Pauly, Daniel, and William W.L. Cheung (2018. Sound physiological knowledge and p inciples in modeling
sh inking o Ƽshes unde clima e change. Global Change Biology, ol.ɸ24, No. 1, pp.ɸe15–e26.
Pineda, Jesʱs, and o he s (2016. A c ab swa m a an ecological ho spo : pa chiness and popula ion den-
si y om AUV obse a ions a a coas al, opical seamoun . Pee J, ol.ɸ4, e1770.
Pö ne , Hans-O. (2012. In eg a ing clima e- ela ed s esso e ec s on ma ine o ganisms: uni ying p in-
ciples linking molecule o ecosys em-le el changes. Ma ine Ecology P og ess Se ies, ol.ɸ470,
pp.ɸ273–290.
Pu cell, Ke in M., and o he s (2017. Flee beha io is esponsi e o a la ge-scale en i onmen al dis u -
bance: Hypoxia e ec s on he spa ial dynamics o he no he n Gul o Mexico sh imp Ƽshe y.
PloS One, ol.ɸ12, No. 8, e0183032.
Rice, Michael A. (2014. Ex ension p og amming in suppo o public policy o he managemen o aqua-
cul u e in common wa e bodies. Aquacul u a Indonesiana, ol.ɸ15, No. 1.
Riebesell, Ul , and Jean-Pie e Ga uso (2015. Lessons lea ned om ocean acidiƼca ion esea ch. Na u e
Clima e Change, ol.ɸ5, No. 1, p. 12.
Rose, Kenne h A., and o he s (2018. Modeling he popula ion e ec s o hypoxia on A lan ic c oake (Mic o-
pogonias undula us in he no hwes e n Gul o Mexico: pa 2Ƃ ealis ic hypoxia and eu ophica-
ion. Es ua ies and Coas s, ol.ɸ41, No. 1, pp.ɸ255–279. h ps://doi.o g/10.1007/s12237-017-0267-5.
Russell, Bayden D., and o he s (2013. Fu u e seag ass beds: Can inc eased p oduc i i y lead o inc eased
ca bon s o age? Ma ine Pollu ion Bulle in, ol.ɸ73, No. 2, pp.ɸ463–469.
Sa o, Ki k N., and o he s (2017. Habi a comp ession and expansion o sea u chins in esponse o changing
clima e condi ions on he Cali o nia con inen al shel and slope (1994–2013. Deep Sea Resea ch
Pa II: Topical S udies in Oceanog aphy, ol.ɸ137, pp.ɸ377–389.
Schmid ko, Sunke, and o he s (2017. Decline in global oceanic oxygen con en du ing he pas Ƽ e dec-
ades. Na u e, ol.ɸ542, No. 7641, p. 335.
Sokolo a, Inna M. (2013. Ene gy-limi ed ole ance o s ess as a concep ual amewo k o in eg a e he
e ec s o mul iple s esso s. In eg a i e and Compa a i e Biology, ol.ɸ53, No. 4, pp.ɸ597–608.
Spe ling, E ik A., and o he s (2016. Biodi e si y esponse o na u al g adien s o mul iple s esso s on
con inen al ma gins. P oceedings o he Royal Socie y B: Biological Sciences, ol.ɸ283, No. 1829,
20160637.
S amma, Lo ha , and o he s (2012. Expansion o oxygen minimum zones may educe a ailable habi a
o opical pelagic Ƽshes. Na u e Clima e Change, ol.ɸ2, No. 1, p. 33.
Sunday, Jenni e M., and o he s (2017. Ocean acidiƼca ion can media e biodi e si y shi s by changing
biogenic habi a . Na u e Clima e Change, ol.ɸ7, No. 1, p. 81.
Ŵŵŵŵ75
Chap e 9: P essu es om changes in clima e and a mosphe e
Teixidʬ, Nu ia, and o he s (2018. Func ional biodi e si y loss along na u al CO2 g adien s. Na u e Commu-
nica ions, ol.ɸ9, No. 1, a . 5149.
Thomas, Pe e , and o he s (2015. Impai ed game e p oduc ion and iabili y in A lan ic c oake collec ed
h oughou he 20,000 km2 hypoxic egion in he no he n Gul o Mexico. Ma ine Pollu ion Bulle in,
ol.ɸ101, No. 1, pp.ɸ182–192.
Thomas, Y., and o he s (2019. E ec s o hypoxia on me abolic unc ions in ma ine o ganisms: Obse ed
pa e ns and modelling assump ions wi hin he con ex o Dynamic Ene gy Budge (DEB heo-
y.ɸJou nal o Sea Resea ch, ol.ɸ143, pp.ɸ231–242.
Vizzini, S., and o he s (2017. Ocean acidiƼca ion as a d i e o communi y simpliƼca ion ia he collapse
o highe -o de and ise o lowe -o de consume s. Scien iƼc Repo s, ol.ɸ7, No. 1, a .ɸ4018.
Wishne , Ka en F., and o he s (2018. Ocean deoxygena ion and zooplank on: Ve y small oxygen di e enc-
es ma e . Science Ad ances, ol.ɸ4, No. 12, eaau5180.
W igh , Jody J., and o he s (2012. Mic obial ecology o expanding oxygen minimum zones. Na u e Re-
iews Mic obiology, ol.ɸ10, No. 6, p. 381.