The environment: understanding Ivorian waters
You only fish well what you understand. This first part describes the stage on which the 106 species in this book live: a tropical ocean crossed by upwellings of cold water, a canal that breathes with the tides, and the largest lagoon system in West Africa. Thirty pages to turn every trip into a reading of the landscape.
Chapter 1: The Gulf of Guinea, an ocean under influence
The Gulf of Guinea is the great indentation of the tropical Atlantic, from Liberia to Gabon. Côte d'Ivoire has more than 500 kilometres of coastline here, alternating open beaches, river mouths and rocky shores in the west. Offshore, the continental shelf slopes gently before plunging: most coastal fishing takes place on this underwater step.
At the surface, the Guinea Current carries warm water eastward, often above 27 °C. Beneath this warm layer, colder, richer water bides its time. The boundary between the two, the thermocline, rises and falls with the seasons: its depth governs where the fish are. When it rises, life rises with it.
Three families of underwater landscapes shape the Ivorian seabed: soft bottoms of sand and mud, the domain of flatfish, croakers and threadfins; rocky outcrops and wrecks, refuges of groupers, snappers and dentex; and open water, territory of sardinella schools and their predators. The species sheets in Part II are sorted according to this logic.
Chapter 2: The Ivorian upwelling, the metronome of fishing
Twice a year, the Ivorian sea changes its face. The water turns murky, its temperature drops by several degrees, and the beaches become cool in the early morning. This is the upwelling: deep, cold, nutrient-rich water rising to the surface. This phenomenon, long documented by oceanographers at the CRO and the IRD, is the true metronome of Ivorian fishing.
The long cold season runs from July to October. The nutrients feed the plankton, the plankton feeds the sardinellas and anchovies, and these huge schools attract every hunter: tunas, jacks, barracudas, Spanish mackerels, seabirds. This is the angler’s high season, from the shore as offshore. A short cold season, briefer and less marked, occurs in January and February: scientists have shown its growing role in sardinella spawning.
In between, the warm, clear waters of November-December and March-June shift the game: pelagic fish move away or go deeper, and bottom fishing and the lagoon take over. The cross-referenced calendar in the appendix sets out this cycle, month by month and species by species.
Chapter 3: The great journey of water
Where does the water you fish in come from? Let us follow a raindrop that falls in the wet season on the savannas of the north. It joins a backwater, then one of the great rivers flowing south: the Comoé, the Bandama, the Sassandra. The journey takes weeks. Along the way, the water picks up sediments, plant debris, everything that will make the estuaries rich.
As it nears the coast, the river slows down and meets its first obstacle: the coastal sand barrier, which the swell constantly rebuilds. Behind it, the fresh water spreads out and forms the lagoons. This is where everything mixes: river water, rainwater, and the salt water that the tides push in through the channels and the Vridi canal. Scientists call it brackish water: neither fresh nor marine, and exceptionally fertile.
The flood changes everything. At the end of the rainy season, the Comoé surges with power and freshens the eastern part of the lagoon system; marine fish retreat towards the channels, freshwater species move down. In the dry season, the movement reverses: the sea gains ground, salinity rises, and with it jacks and barracudas push far into the lagoon. The lagoon angler fishes in an environment that breathes over the course of a year.
Then the water leaves again. Through the channels, each ebb tide returns a little of the journey to the ocean: brown, nutrient-laden water, fry carried out to sea; the plume can be seen from the beach. The sun takes back its share through evaporation, clouds form rain again, and the cycle starts over. When you fish a river mouth, you are fishing the exact meeting point of this cycle.
Chapter 4: The Vridi canal, the beating heart
On 23 July 1950, after decades of failure against the sand, Abidjan’s coastal sand barrier was breached. The Vridi canal, 2.7 kilometres long and about 370 metres wide, finally linked the Ébrié lagoon to the ocean. It made Abidjan a major port. And, without anyone planning it, it created one of the most unusual ecosystems in West Africa. Widened and deepened in 2019, it remains the lagoon’s only marine breathing channel.
Twice a day, the tide pushes ocean water into the canal; twice a day, the lagoon responds. This ebb and flow mixes salt and brackish water, carries larvae, and concentrates prey in the currents. For fish, the canal is at once a gateway, a larder and a migration corridor: threadfins and jacks come in to hunt, and juveniles use it to reach their lagoon nurseries.
For the angler, Vridi is a school. The same day offers several kinds of fishing: slack water, the calm moment at the turn of the tide, favours bottom fishing; the running current concentrates feeding frenzies along the riprap. But the canal is first and foremost an active port facility: prohibited zones, constant traffic, strict regulations. This book returns to it in the chapter on jetty fishing.
The Trou sans fond: a canyon at the city’s gates
In exact line with the canal, the seabed collapses. The Trou sans fond (“Bottomless Pit”), identified as early as 1889 by the explorer Binger, is a submarine canyon that cuts into the continental shelf off Abidjan and plunges to more than 3,000 metres. It long complicated the breaching of the coastal sand barrier, and today it is what makes fishing in Abidjan unique: ocean depths a few miles from the coast.
For fish, the canyon is an elevator: its walls concentrate currents, bring up rich water and anchor life. Its rocky edges, between 50 and 100 metres, shelter groupers, snappers, dentex and seabreams; its abyss brings deep-sea species, rarely found so close to shore elsewhere, past Abidjan. The handline chapter in Part III details this unique fishery. Scientists rank the area among the ecologically significant marine areas of the Gulf of Guinea, while warning that the canyon also receives the city’s discharges.
Chapter 5: The lagoons, an inland sea
Behind the coastal sand barrier, Côte d'Ivoire hides a second seafront: nearly 300 kilometres of lagoons strung together, from Assinie to Fresco. The Ébrié lagoon is its centrepiece: about 560 km² and 130 kilometres from east to west, with an average depth of less than 5 metres. Abidjan was built on it, around it, within it. To the east, the Aby lagoon shares its waters with Ghana; to the west, the Grand-Lahou system receives the Bandama.
The lagoon is not a uniform expanse: it is a mosaic of habitats. Near the Vridi canal, the water is distinctly salty and marine species abound. Towards the ends and the river mouths, the water becomes fresher and freshwater species appear. In between, every bay, every island, every 3-metre bottom has its own community. The lagoon angler learns his lagoon as a shepherd learns his pasture.
On the banks, the mangrove. Mangrove trees, which grow with their feet in brackish water, are much more than scenery: their tangled roots are the largest nursery in the region. Shrimps, threadfin fry, young tilapias: everyone grows up there, sheltered from predators. An hour of fishing near a mangrove edge tells you more than any treatise.
The Ébrié lagoon is also an environment under pressure: the country’s largest city discharges part of its wastewater into it, sand is dredged, some bays run out of oxygen. The work of the CRO Abidjan has documented these changes for decades. Part V of this book devotes a whole chapter to it, because the future of Ivorian fishing is decided here first.
Chapter 6: Three habitats, one playground
Let us sum up the stage. The lagoon habitat: calm, brackish, shallow water, the realm of the Bagrid catfish and the Blackchin tilapia, accessible to all. The estuarine habitat: channels, river mouths and the canal, where everything mixes and the big coastal predators hunt. The marine habitat: from the beach to the open ocean, from surfcasting to marlin, set to the rhythm of the upwelling.
These three habitats are connected, and their inhabitants move between them. That is the great lesson of this first part, and the key to reading everything that follows: never just ask which fish you are after, ask which water it is in this month. The colour code of the species sheets, the habitat banner at the top of each species and the calendar in the appendix are designed to answer that question.