El Niño as a predictor of round sardinella distribution along the northwest African coast

Abstract

The El Niño Southern Oscillation (ENSO) produces global marine environment conditions that can cause changes in abundance and distribution of distant fish populations worldwide. Understanding mechanisms acting locally on fish population dynamics is crucial to develop forecast skill useful for fisheries management. The present work addresses the role played by ENSO on the round sardinella population biomass and distribution in the central-southern portion of the Canary Current Upwelling System (CCUS). A combined physical-biogeochemical framework is used to understand the climate influence on the hydrodynamical conditions in the study area. Then, an evolutionary individual-based model is used to simulate the round sardinella spatio-temporal biomass variability. According to model experiments, anomalous oceanographic conditions forced by El Niño along the African

The Sound of Silence: An Immersive Approach to Spearfishermen's Ecological Knowledge Along the Dakar Coastline

“…The concept of “ gane ” (guest/immigrant/foreign) versus local Grouper is in line with previous observations that have suggested the existence of both migrant and sedentary Grouper populations around the Cape Verde peninsula, and thus reinforces this hypothesis (Cury and Roy 1988). The lag of migrating fish arrival in Dakar during the transition between the rainy and cold seasons is in line with recent oceanographic research (Lopez-Parages et al 2019) that links the migratory behavior of a typical migratory species performing migrations between Senegal and Mauritania ( S. aurita ) to global climate indices. Climate change scenarios generally predict a weakening of the upwelling in Senegal (Sylla et al 2019); this could further increase the migration lag for the species mentioned by spearfishermen, and, according to the order of migration they describe, some of the migratory species may not reach Dakar anymore.…”

Dynamics of anchovy and sardine populations in the Canary Current off NW Africa: Responses to environmental and climate forcing in a climate‐to‐fish ecosystem model

“…Overall, variation in annual sardine and anchovy populations were most tightly connected to the NAO and AMO, respectively (Figure 11). ENSO, which has also been related to variability of clupeids off NW Africa (e.g., migration patterns of Sardinella aurita ; López‐Parages et al., 2020), seems to play a secondary role in the dynamics of anchovy and sardine in our model. The identified anchovy sensitivity to larval drift mortality also suggests that anchovy can be particularly vulnerable to future climate scenarios that project enhanced along‐shore winds in EBUS (Bakun, 1990).…”

Southeastern Tropical Atlantic Changing From Subtropical to Tropical Conditions

“…In fact, small pelagic fishes are sensitive to climate variability (Bakun et al, 2015;López-Parages et al, 2020;Peck et al, 2021). For instance, variations in temperature and food availability can lead to migrations of small pelagic fishes and to changes of their behavior (Brochier et al, 2018;López-Parages et al, 2020). Our observed stratification transition from subtropical to tropical conditions associated with a warmer mixed layer is likely to impact the small pelagic fishes in the SETA region.…”

“…Understanding the consequences of enhanced stratification on primary productivity is key as this will have further impact on the marine food web. In fact, small pelagic fishes are sensitive to climate variability (Bakun et al, 2015;López-Parages et al, 2020;Peck et al, 2021). For instance, variations in temperature and food availability can lead to migrations of small pelagic fishes and to changes of their behavior (Brochier et al, 2018;López-Parages et al, 2020).…”