Deep-sea ecosystems off Mauritania : research of marine biodiversity and habitats in the Northwest African Margin

692 Pages·2017·38.53 MB·English

by  Ramil, Fran, Ramos, Ana, Sanz, José Luis

Ana Ramos · Fran Ramil
José Luis Sanz Editors
Deep-Sea
Ecosystems Off
Mauritania
Research of Marine Biodiversity and
Habitats in the Northwest African
Margin
Deep-Sea Ecosystems Off Mauritania
The giant barrier of carbonate mounds undoubtedly constitutes the main geomor-
phologicalandbiologicalfeatureintheMauritanianslope.Inthepicture,asceneof
cold-water corals sampling on board the oceanographic vessel Vizconde de Eza
during the Maurit Surveys.
Ana Ramos Fran Ramil
(cid:129)
é
Jos Luis Sanz
Editors
Deep-Sea Ecosystems Off
Mauritania
Research of Marine Biodiversity and Habitats
in the Northwest African Margin
123
Editors
Ana Ramos JoséLuisSanz
Instituto Español deOceanografía Instituto Español deOceanografía
Vigo Madrid
Spain Spain
FranRamil
Facultade deCiencias doMar
Universidade deVigo
Vigo
Spain
ISBN978-94-024-1021-1 ISBN978-94-024-1023-5 (eBook)
DOI 10.1007/978-94-024-1023-5
LibraryofCongressControlNumber:2017939900
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In memoriam: Luis Quintanilla
For our dear teammate and friend, who left
us before he could see this Mauritanian
volume published.
For all marine researchers who ventured
before us into the beautiful Mauritanian sea
off the Sahara shores.
Foreword
Fourmajorupwellingsystemshavebeenidentifiedworldwide.Theyextendoffthe
westerncoastsofbothhemispheresoftheAmericanandAfricancontinents,where
permanent trade winds blow. It is paradoxical that the extremely arid lands of
California, Peru, Namibia, and the Sahara could hold under the surface of their
neighbouring seas such diverse, rich, productive and complex ecosystems with
fantasticmarinerealms.Specificmeteorologicalandoceanographicprocessesoccur
indesertsand seas, whichmake thecoexistence ofthe two contrastingbutequally
fascinating landscapes possible.
Scientificknowledgeontheupwellingsystemsisalsoquitediverse.Someofthe
systemshavebeensystematicallymonitoredandstudiedfordecades,whilethereis
limited information on the others. This is the case with the Cape Blanc upwelling
system, which is located on the Saharan coast (Northwest Africa), approximately
between Cape Bojador (26°N) and Cape Timiris (19°N).
Thisregioncorrespondstooneoftherichestfishinggroundsintheworld,where
important fisheries have been located since the fifteenth century. Portuguese
explorers, who navigated the African coast on their way to the East, recorded the
first reports of these fish resources. Fishermen from the Canary Islands exploited
them exclusively for centuries until fleets from Europe moved down to the south
duringthetwoWorldWars,lookingforfreefishinggroundsawayfromtheareasof
conflict.Industrializationdidtherest,andintheseventiesofthetwentiethcentury,
an international fleet of a couple of thousand vessels was fishing in the area for
diversespeciesoffinfish,cephalopodsandcrustaceans.Currently,theareaisunder
the administration of Mauritania and Morocco, and access to the resources is
regulated by bilateral fishing agreements with interested parties, such as the
European Union.
Information on species, habitats, climatic and oceanographic conditions, fish-
eriesandfishermenhasbeenaccumulatedthroughoutthecenturies,inparallelwith
proper fishing activities. Since the seventeenth century, several researchers have
described the way of life of the fishermen in the area and recorded the type of
vessels; fishing grounds; fishing gear; species caught, including commercial and
non˗commercial species; preservation methods and traditions. Most of these
vii
viii Foreword
publications are strictly descriptive and based on the empirical knowledge of the
fishermen rather than the personal observations of the researchers.
Properscientificresearchintheareastartedwithsomeexpeditionsconductedin
thenineteenthcentury,suchasthehistoricalChallenger,whichpassedthroughthe
area and collected samples that were analysed to catalogue or describe the marine
species and environmental conditions. Thus, information on the region was accu-
mulated in a somewhat chaotic manner; the literature is sparse, and specific
references are difficult to find.
ThemostimportantimpulsetotheresearchontheCapeBlancupwellingsystem
(and, by extension, the Mauritanian marine ecosystem) was provided by the
InternationalCouncilfortheExplorationoftheSea(ICES),whichin1969,together
with the Intergovernmental Oceanographic Commission (IOC), proposed to carry
out a project called the Cooperative Investigation of the Northern Part of the
Eastern Central Atlantic (CINECA). The operational phase of CINECA occurred
between 1970 and 1979, with the involvement of 14 countries and 30 research
vessels that conducted around 100 surveys along the coast of the former Western
Sahara and Mauritania. The results of the project led to the creation of the FAO
Committee for the Eastern Central Atlantic Fisheries (CECAF), which, since then,
has played an important role in the marine research of its area of jurisdiction,
particularly with respect to fishing resources.
Nevertheless, and despite very important efforts made by individual scientists
and research groups, most of the studies on ecosystem components other than fish
werealmostabandonedsincetheendoftheCINECAproject,or,atleast,theywere
not conveniently or easily made visible and/or available to the scientific
community.
Conscious of this lack of crucial information on the Cape Blanc upwelling
system, the Ecosystem Approach to the Fisheries Management (EAFM), Instituto
Español de Oceanografía (IEO) and Institut Mauritanien de Recherches
Océanographiques et des Pêches (IMROP) decided to conduct a series of multi-
disciplinary demersal surveys along the Mauritanian coast down to 2000 m depth.
These surveys were organized in collaboration with the Spanish Secretary for
Fisheries(MinistryofAgriculture,FoodandEnvironment),whocontributedtothe
project by providing the research vessel Vizconde de Eza and a substantial part
of the budget.
Themost relevant resultsofthis series ofcollaborativesurveysarepresented in
this volume. The volume contains 17 chapters that include an introduction and a
final recapitulative chapter, integrating all the current knowledge on the demersal
and benthic ecosystems along the Mauritanian coast, identifying known and new
habitats, cataloguing the biodiversity (species, assemblages and communities),
describing major oceanographic features and, for the first time, mapping in detail
the sea bottom and a large number of previously unknown canyons and proposing
new ideas and approaches for their management according to the EAFM.
This is a huge and impressive work that defines the Mauritanian marine
ecosystem. Written with enthusiasm, scientific rigour, intelligence and, above all,
agenerouscollaborativespiritinvolvingscientistsandinstitutionsfromMauritania
Foreword ix
andSpain,wearesurethatthisbookwillbeareferenceworkforallscientistswho
intend to deepen their understanding of the fascinating waters of Mauritania.
We offer our most sincere gratitude and congratulations to the authors for their
magnificent work and continuous contribution to marine research in Africa.
August 2016 Dr Eduardo Balguerías Guerra
Director
Instituto Español de Oceanografía
Madrid, Spain
Dr Mohamed Mbarek O. Sweilem
Director
Institut Mauritanien de
Recherches Océanographiques
et des Pêches
Nouadhibou, Mauritania
Preface
When we thought of preparing this volume, our intention was to compile, in a
single volume, the main results of our research on the Mauritanian continental
margin in 2007–2010, carried out within the framework provided by the bilateral
cooperation between the Spanish Institute of Oceanography and the Mauritanian
Institute for Fisheries and Oceanographic Researches.
Originally, the four Maurit surveys were meant to prospect and evaluate deep
demersal resources; however, the discovery of the amazing features hidden in the
Mauritanianslopeshiftedtheoriginalgoaltowardscollatingintegralinformationon
the ecosystems and a better understanding of the processes that control the biodi-
versityandabundanceofthefishingresources.Wearescientists,andinthefaceof
this challenge, we could not restrain ourselves. We hope that our Mauritanian
colleagues will forgive us in the light of the results obtained!
Completing the edition of this volume consumed much more time than we
expected at the beginning of this journey, when we presented the project and
Springeraccepted its publication. However, despite many obstacles, mainly dueto
difficult personal circumstances, we managed to finish this task with the same
eagerness that we had three years ago, when this book was only an idea.
We did not have grand equipment or sophisticated technology on˗board the R/V
VizcondedeEza,butwehadafirst-classworkteam,and,becauseofthat,wearehighly
satisfiedwithourresults.Thisbookshowsthatwithgoodplanningandminimumaddi-
tionalcost,demersalsurveyscanbecomeexcellentplatformsforexpandingourknowledge
onmarineecosystemsinpoorlyresearchedregions,suchastheNorthwestAfricancoast.
For those of us who love that continent and have devoted over 20 years to
contributing towards the research of the African seas, it is extremely satisfying to
introduce this volume on Mauritanian deep˗water ecosystems, which undoubtedly
will become an important reference for marine research in Northwest Africa.
Vigo, Spain Ana Ramos
Vigo, Spain Fran Ramil
Madrid, Spain José Luis Sanz
December 2015
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