The Great African Expedition: fisheries research near the coast of Mozambique on the RV «Atlantida» in 2025. Preliminary results

Objective: To present preliminary results of a study of the status of aquatic biological resources and their habitats in the Mozambique area.

Materials and Methods: A bottom trawl survey was conducted in the Mozambique area from March to May 2025 on the STM Atlantis to estimate the biomass of demersal fish and invertebrates. The comprehensive survey also included hydrometeorological, oceanographic, hydrochemical, hydrobiological, and ichthyological studies. The work was carried out in accordance with modern Russian and international methodologies.

Results: The environmental conditions were characterized by the following features: variability of weather parameters from 7 to 30 days, active meandering of the Mozambique Current, noticeable freshening of surface waters (0–10 m), the presence of several pronounced layers of jumps in thermohaline and hydrochemical parameters of waters in the depth range from the surface to 1000 m. The distribution of seston and chlorophyll «a» was closely associated with areas of water upwelling, as well as with the influx of biogens onto the shelf with river runoff. The total estimated biomass of aquatic biological resources was 246,000 tons. The demersal community was characterized by high species diversity — 611 fish species and 258 invertebrate taxa. Among fish, the largest biomass was observed among the cigar jack mackerel, common scimitarfish, cleavers, and Lessepsian saurid. Invertebrates accounted for approximately 15% of the total biomass. Acoustic monitoring of the survey did not reveal significant commercial aggregations of fish or invertebrates.

Novelty: Up-to-date data on the status of aquatic biological resources and their habitats were obtained. Practical Relevance:

The results will be used to assess fishery prospects and prepare recommendations for fisheries management in the Mozambique area.

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