*Co esponding au ho : Se igne Abdoul Aziz NDAW
Copy igh © 2025 Au ho (s) e ain he copy igh o his a icle. This a icle is published unde he e ms o he C ea i e Commons A ibu ion License 4.0.
Pe cep ions o local communi ies on Hann Bay and solu ions o sus ainable
de elopmen
Se igne Abdoul Aziz NDAW 1, 2, *, Se igne FAYE 1, Rama oulaye Mbengue NDIAYE 1 and Mouhamadou Bachi
DIOUF 1
1 Facul y o Sciences, Wa e and Wa e Quali y Doc o al School (EDEQUE) – Cheikh An a Diop Uni e si y, Daka , Senegal.
QES Consul ing In e na ional.
2 Bo any-Biodi e si y Labo a o y, Depa men o Science and Technology, Cheikh An a Diop Uni e si y, BP 5005, Daka
Fann, Senegal.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
Publica ion his o y: Recei ed on 27 Augus 2025; e ised on 17Oc obe 2025; accep ed on 20 Oc obe 2025
A icle DOI: h ps://doi.o g/10.30574/gscbps.2025.33.1.0380
Abs ac
Socio-economic su eys conduc ed among local popula ions and wo ke s in indus ial uni s made i possible o in ol e
key s akeholde s in he decision-making p ocess and o in eg a e hei opinions, expec a ions, sugges ions, and
ecommenda ions. The p oposed solu ions ocus p ima ily on p o ec i e and p e en i e measu es, en o cemen o
egula ions, communica ion and awa eness campaigns, acquisi ion o app op ia e equipmen , and moni o ing–
su eillance sys ems o suppo he ehabili a ion o Hann Bay and ensu e i s long- e m sus ainabili y.
These su eys we e ca ied ou in 2022 ac oss ele en si es loca ed in he municipali ies o Hann-Bel Ai , Dali o Foi ail,
Thia oye-su -Me , Sicap Mbao, and Mbao. They p o ided a pa icipa o y pla o m ha shed ligh on bo h he
en i onmen al and socio-economic challenges acing Hann Bay.
The indings e ealed ha chemical pollu ion emains p esen in he bay, which may lead o con amina ion o ishe y
esou ces o push ish popula ions u he o sho e. The deg ada ion o ecological condi ions could also explain he
equen mo ali y o ju enile ish, pa icula ly in a eas such as Hann Ma inas, Hann Pêcheu s, and Ci é ISRA (see ield
obse a ions, July 2022, Se igne Abdoul Aziz Ndaw).
In his pe spec i e, he s udy goes beyond a simple diagnos ic o also p opose an in eg a ed se o solu ions p omo ing
sus ainable de elopmen o he a ea. The a ge zone is home o nea ly 500,000 esiden s, hund eds o indus ial
uni s—mos o which lack adequa e sani a ion sys ems—as well as a wide ange o local s akeholde s, including
communi y leade s and municipal council membe s. The da a collec ion elied on bo h quali a i e and quan i a i e
app oaches, using a combina ion o open-ended and closed-ended ques ions, he la e equi ing esponden s o answe
wi h a simple “yes” o “no.”
Keywo ds: Su eys; Pollu ion; Sedimen s; Hann Bay; Senegal
1. In oduc ion
In Senegal, he issue o pollu ion in Hann Bay has been a he cen e o conce n, mobilizing he S a e and a ious
s akeholde s o decades. Wi hin he amewo k o his s udy on communi y pe cep ion, he aim is o in ol e he
conce ned pa ies in he decision-making p ocess in o de o ake in o accoun hei pe cep ions, opinions, expec a ions,
and ecommenda ions. The a ge a ea o Hann Bay, loca ed sou h o he Cape Ve de Peninsula and eas o he ci y o
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
311
Daka , ex ends o e app oxima ely 17 km. I is bounded o he no h by he Old Ru isque>Road, o he sou h by Hann
Bay, o he wes by he mili a y base, and o he eas by he illage o Pe i Mbao. Once a highly equen ed si e, Hann
Bay oday ecei es subs an ial olumes o was ewa e and con ains hea ily pollu ed sedimen s. Indeed, apid
u baniza ion has b ough indus ial a eas close o esiden ial zones, he eby in ensi ying en i onmen al and heal h
p essu es.
This s udy he e o e seeks o add ess wo main esea ch ques ions:
• Wha a e he conce ns o he s akeholde s in ol ed in he bay?
• Wha can be ou con ibu ion o he ehabili a ion o he bay in suppo o sus ainable de elopmen ?
2. Ma e ial and me hods
2.1. S udy A ea
The Hann-Mbao s udy a ea ( igu e 1) is composed o se e al municipali ies, indus ial acili ies, households, and a ious
human ac i i ies ha gene a e pollu ion h ough bo h di ec and clandes ine discha ges in o he bay o in o pi s. The
main dis ic municipali ies (Hann-Bel Ai , Dali o Foi ail, Thia oye-su -Me , Sicap Mbao, and Mbao) mos a ec ed by
he deg ada ion o he bay ha e expanded signi ican ly. Howe e , due o he lack o sani a ion in as uc u e and
adequa e sys ems o was e collec ion and disposal, local esiden s o en dump hei solid was e on he beach o di ec ly
in o he bay. This si ua ion has se e e ecological, sani a y, and isual consequences, which in u n nega i ely impac he
sus ainable managemen o Hann Bay.
The a ge popula ion includes esiden s om he a ious neighbo hoods, leade s o communi y associa ions,
businesses, and membe s o he municipal council. These local s akeholde s a e expec ed o p o ide he necessa y da a
h ough bo h quali a i e and quan i a i e su eys.
Finally, in ca ying ou he quan i a i e su ey, he ques ions o mula ed we e bo h open-ended and closed-ended, he
la e equi ing esponden s o answe wi h a simple “yes” o “no.”
Sou ce: Au ho , July 2022
Figu e 1 S udy A ea
2.2. Su ey Si es
The su ey si es we e loca ed in he municipali ies s e ching om Hann o Mbao. All neighbo hoods we e included in
he su ey. In o al, 160 ques ionnai es we e adminis e ed o he local popula ions.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
312
The neighbo hoods isi ed in Hann we e: Hann Yen, Hann Pêcheu , Hann Fe aille, Hann Mon agne 5, Hann Mon agne
6, Hann Ma igo , and Hann Plage.
The neighbo hoods isi ed in Dali o we e: Eaux e Fo ê , Fo ces A mées, Ci é Ma ine, Da ou Salam, Ci é Mai ie, Ci é
Deggo, Touba Se as, Ci é Mo Ma y Sa , and Ci é Cas o s Municipaux.
The neighbo hoods isi ed in Thia oye we e: Thia oye-Ga e, Thia oye-su -Me , and Thia oye-Kao.
The neighbo hoods isi ed in Mbao we e: Pe i Mbao (Lébou and Peul), G and Mbao, Keu Mbaye Fall, and Ci é Ndeye
Ma ie.
2.3. Sampling Me hod
The me hod used in his s udy was simple andom sampling, which is pa o he p obabilis ic su ey me hods. A sample
is de ined as a ela i ely small g oup, scien i ically selec ed in such a way as o ep esen he pa en popula ion as
ai h ully as possible. Ins ead o examining he en i e popula ion, only a po ion o i is s udied, p o ided ha i is
ep esen a i e, and conclusions a e hen d awn o he whole popula ion.
As shown in Table 1, a quo a o app oxima ely o y ques ionnai es was adminis e ed o esiden s in each o he
ollowing municipali ies: Hann-Bel Ai , Dali o , Thia oye-su -Me , Sicap Mbao, and Mbao.
2.4. Sampling o Responden s
Gi en he demog aphic weigh o each municipali y, sampling was conduc ed, and i was deemed necessa y o ga he
he pe spec i es o men and women, you h, adul s, and he elde ly.
In e iews wi h esiden s o he s udy a ea we e ca ied ou on samples designed as educed models o he o e all
popula ion. The selec ion o hese samples aimed o achie e he highes possible ep esen a i eness.
A eliable scien i ic s udy is only as s ong as he quali y o he ools o ins umen s used o da a collec ion. Fo his
pu pose, a ques ionnai e was adminis e ed by sec o .
Table 1 Numbe o Ques ionnai es Adminis e ed pe Sec o
Sec o
Popula ion
O de
Dénomina ion
Numbe o In e iews
Sec o 1
Hann Bel Ai
40
Sec o 2
Dali o
40
Sec o 3
Thia oye
40
Sec o 4
Mbao
40
TOTAL
160
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
In addi ion, semi-s uc u ed in e iews we e conduc ed using a ques ionnai e adminis e ed o local o icials, indus ial
s akeholde s, and adminis a i e se ices. The ques ions we e o mula ed in ela ion o socio-economic ac i i ies and
en i onmen al policies.
3. Resul s and discussion
The analysis and in e p e a ion o he su ey esul s a e based bo h on documen a y and bibliog aphic da a, and on
ield obse a ions collec ed du ing in e iews conduc ed wi hin he s udy a ea. O e all, he indings highligh se e al
key issues conce ning Hann Bay, including he mos signi ican en i onmen al p oblems, he se lemen his o y o he
local popula ions, and he impac s o pollu ion on economic, ou ism, indus ial, and comme cial sec o s.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
313
3.1. Dis ibu ion o Responden s by Na ionali y
The analysis o na ionali y e eals ha 100% o esponden s su eyed in Hann Bel-Ai , Dali o , Thia oye, and Mbao a e
o Senegalese na ionali y.
3.2. Dis ibu ion o Responden s by Age (%)
Mos indi iduals su eyed du ing his s udy we e abo e 30 yea s o age, e lec ing a ela i ely ma u e popula ion. This
age p o ile indica es ha esponden s a e gene ally awa e o he pollu ion in Hann Bay and i s impac s on hei
li elihoods.
In Hann Bel-Ai , 46% o esponden s we e aged be ween 45 and 60 yea s, 35% we e be ween 30 and 45 yea s, and 19%
we e o e 60 yea s old.
In Dali o and Thia oye, 44% o esponden s we e be ween 30 and 45 yea s, while he 18–25 age g oup and
esponden s o e 50 yea s each ep esen ed 28% o he sample.
In Mbao, 41% o esponden s ell wi hin he 30–45 age g oup. The 18–25 age g oup accoun ed o 32%, while hose
aged 50 and abo e ep esen ed 27% o he sample.
In summa y, indi iduals aged30 o 45 ep esen he mos signi ican po ion o he sample ac oss he a ea ex ending
om Hann o Mbao (see G aph). Ha ing g own up wi h he pollu ion o he bay, hei iews, conce ns, sugges ions, and
ecommenda ions we e gi en conside a ion.
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 2 Dis ibu ion o Responden s by age (%)
3.3. Dis ibu ion o esponden s acco ding o he du a ion o esidence (%)
Mos esponden s a e well acquain ed wi h Hann Bay, as hey ha e been esiding in he a ea o se e al decades, on
a e age a ound hi y yea s.
• In Hann Bel-Ai :
73% o esponden s ha e li ed in he a ea o a pe iod anging om 25 o 65 yea s (see Figu e 13). This demons a es
ha hey possess in-dep h knowledge o bo h he e olu ion o pollu ion in he bay and he a ious measu es
implemen ed o i s managemen .
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
314
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 3 Dis ibu ion o esponden s acco ding o he du a ion o esidence (%) in Hann
In Dali o and Thia oye, 28% o esponden s a e na i es (see Figu e 2). Fo non-na i e esiden s, he numbe o yea s
o esidence anges om 2 o 35 yea s. The mos ecen a i als a e hose who se led in he a ea a ound 2 yea s ago.
Sou ce : Se igne Abdoul Aziz NDAW, July 2022
Figu e 4 Dis ibu ion o esponden s by du a ion o esidence (%) in Dali o and Thia oye
In Mbao, 38% o he esponden s a e na i es o he locali y (see Figu e). Fo hose who a e no o iginally om he
di e en neighbo hoods, he leng h o esidence anges be ween 2 and 30 yea s. The esponden s who ha e mos
ecen ly se led in he neighbo hoods o Mbao ha e been li ing he e o only 2 yea s.
Figu e 4 illus a es he in e ac ions ca ied ou du ing he su eys wi h esiden s li ing nea SOGAS. These in e ac ions
made i possible o conside hei opinions, conce ns, and sugges ions.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
315
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 5 Dis ibu ion o esponden s acco ding o leng h o esidence in Mbao (%)
Sou ce: Se igne Abdoul Aziz NDAW, July 2020
Figu e 6 Field su eys wi h esiden s li ing nea SOGAS
3.4. Majo p oblems ela ed o Hann Bay
• In Hann Bel-Ai , Dali o , Thia oyeand Mbao
Acco ding o he esponden s, he main p oblem is indus ial pollu ion, no ably h ough uncon olled canals, leading o
bo h wa e pollu ion and ai pollu ion, he la e being cha ac e ized by he gene a ion o s ong oul odo s. In addi ion,
o hese popula ions, he Go e nmen is conside ed he p ima y pollu e , pa icula ly h ough ONAS, which does no
su icien ly moni o he discha ges channeled h ough Canal 6, o iginally designed o ain all wa e d ainage.
Responden s also iden i ied he Po as a majo pollu e , due o oil spills, was ewa e discha ged om ships, and
household was ewa e ha is also eleased in o he sea.
O e all, he analysis o esponden s’ pe cep ions o he mos signi ican p oblem associa ed wi h Hann Bay shows ha
84% belie e he main issue is ai pollu ion (odo s) and wa e pollu ion, while 16% iden i y soil pollu ion as he mos
c i ical p oblem (see Figu e). The ollowing igu e illus a es he dis ibu ion o esponden s acco ding o hei
pe cep ion o he mos impo an p oblem linked o Hann Bay.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
316
This si ua ion explains he cu en s a e o Hann Bay, which oday ep esen s an ecological ime bomb o he
su ounding popula ions.
Sou ce: Se igne Abdoul Aziz NDAW, July 2020
Figu e 7 Field su eys wi h esiden s li ing nea SAR
Figu e 7 illus a es he in e ac ions ca ied ou du ing he ield su eys wi h esiden s li ing nea SAR. These
in e ac ions made i possible o ake in o accoun hei opinions, conce ns, and sugges ions.
In summa y, acco ding o he esponden s, he mos impo an p oblem a ec ing Hann Bay is wa e pollu ion. This
pollu ion is isible along he en i e bay, has ad e se e ec on public heal h, and gene a es nuisance odo s.
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 8 Pe cen age dis ibu ion o he majo p oblem ela ed o Hann Bay (%)
3.5. Analysis o economic ac i i ies
3.5.1. Tou ism Ac i i ies Acco ding o Responden s
Tou ism ac i i ies a e i ually non-exis en h oughou he s udy a ea. The se e e pollu ion o Hann Bay has a nega i e
impac on ou ism and signi ican ly hinde s local ini ia i es in his sec o .
• In Hann Bel-Ai
Tou ism no longe gene a es any bene i s o he local popula ion, due o he inc eased pollu ion o he bay and he
insecu i y p e ailing in ce ain a eas, pa icula ly sou h o he Hann ishing wha . This is also whe e he Daka Sailing
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
317
Club (Club des Voilie s de Daka , CVD) is loca ed. In he pas , acco ding o local ishe men, he club used o welcome
in e na ionally enowned isi o s, including celeb i ies such as Bonis Pea s.
• In Dali o
Fo he esiden s o Dali o , ou ism has been absen o se e al yea s. Su ey esul s show ha 85% o he popula ion
conside s ou ism ac i i ies no longe signi ican , while only 15% belie e hey s ill hold some impo ance (see Figu e).
• In Mbao
Acco ding o esiden s, ou ism has been a a s ands ill o yea s. They epo ha ou ism ac i i ies no longe p o ide
any bene i s o he communi y.
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 9 Dis ibu ion o Tou ism Ac i i ies (%)
3.5.2. Comme cial Ac i i ies Acco ding o Responden s
O e all, esponden s in he s udy a ea epo ed ha comme ce is he main economic ac i i y, bu i emains closely
linked o he a ailabili y o ishe y esou ces.
• In Hann Bel-Ai
The Hann Fishing Wha se es as a hub o he emba ka ion o a isanal canoes a i ing om a ious loca ions.
Economic ac i i ies la gely depend on he daily ca ches o ishe men and he a ailabili y o ma ine esou ces. Small-
scale ade is h i ing, pa icula ly in ood se ices, including es au an s and s ee endo s selling juices, peanu s,
mangoes, g illed ish, and simila p oduc s. All esponden s (100% o he sample) iden i ied comme ce as he p ima y
ac i i y.
• In Dali o
Analysis o su ey da a indica es ha all esponden s (100% o he sample) iden i ied comme ce as he main ac i i y,
pa icula ly in connec ion wi h he apid g ow h o he popula ion.
• In Mbao
Su ey esul s show ha mos esponden s (62% o he sample) conside comme ce o be he main ac i i y, linked o
he apid popula ion g ow h. Con e sely, 38% pe cei e i as less impo an .
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 10 Dis ibu ion o Comme cial Ac i i ies (%)
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
318
3.5.3. Ag icul u al Ac i i ies Acco ding o Responden s
O e all, he analysis o he con ibu ion o ag icul u al ac i i ies in his a ea shows ha hey ha e come o a s ands ill.
This si ua ion is mainly explained by pollu ion and inc easing u baniza ion.
• In Hann Bel-Ai
Ag icul u e is almos non-exis en in his a ea, which was o me ly a ishing and a ming illage. Today, ag icul u al
land has been o e aken by u ban expansion. The only emaining p ac ices a e ound in Hann Ma is es, whe e ma ke
ga dening and ho icul u e con inue o exis . These ac i i ies con ibu e o he local economy by gene a ing income o
households pe o ming ho icul u e and ma ke ga dening.
• In Dali o
Su ey da a indica e ha 87% o he popula ion conside ag icul u al ac i i y unimpo an . Con e sely, 13% ecognize
i s posi i e con ibu ion, mainly h ough ma ke ga dening and ho icul u e.
• In Mbao
The analysis shows ha ag icul u al ac i i ies in his a ea ha e been a a s ands ill o many yea s. Residen s epo ha
ag icul u e no longe p o ides any bene i s, as all a ailable land is pollu ed.
3.5.4. Indus ial Ac i i ies Acco ding o Responden s
Acco ding o esponden s, indus ial ac i i ies con ibu e o en i onmen al pollu ion despi e hei economic
impo ance. Mo eo e , indus ial ac i i y in he a ea is no pe cei ed posi i ely in Hann, Dali o , o Mbao.
• In Hann / Dali o / Mbao
Due o i s p oximi y o he Daka Au onomous Po , he municipali y o Hann Bel-Ai hos s a ound one hund ed
indus ies. These indus ies employ local wo ke s, pa icula ly hose who did no pu sue ishing as an occupa ion.
Howe e , hei con ibu ion is no widely pe cei ed in a a o able ligh . The analysis o indus ial ac i i ies indica es
ha mos esponden s (54% o he sample) conside indus ial ac i i y o be impo an . Con e sely, 46% belie e i is
no (see Figu e 8).
Sou ce: Se igne Abdoul Aziz NDAW, July 2022
Figu e 11 Pe cep ion o he Impo ance o Indus ial Ac i i ies Among he Popula ion o Hann, Dali o , and Mbao (%)
Figu e 11 illus a es discussions sessions conduc ed du ing ield su eys wi h wo ke s a Mèches Linda (indus y).
These in e ac ions made i possible o ge hei opinions, conce ns, and sugges ions. I was no ed ha no all indus ies
ha e implemen ed p e- ea men sys ems o was ewa e . Many ely on he Go e nmen o p o ide bo h inancial and
echnical suppo o ensu e be e managemen o hei discha ges.
GSC Biological and Pha maceu ical Sciences, 2025, 33(01), 310-325
325
[3] Dieng, Alassane (Ma ch 2022), Coo dina o o he Hann Bay Depollu ion P ojec , Na ional Sani a ion O ice o
Senegal (ONAS), indi ec ci a ion, www.onas.sn, 1 p. “The depollu ion wo ks o Hann Bay we e launched on
Decembe 25, 2020.”
[4] S ee ing Commi ee Repo , 2014 Hann Bay.
