Distribution and abundance of meiofauna in a Subtropical Coastal Lagoon in the south-eastern Gulf of California, Mexico

The composition and density of meiofauna in Ensenada del Pabellón Lagoon (south-eastern Gulf of California) was evaluated in terms of carbon and nitrogen content, and granulometry. Meiofauna density ranged from 50.0 to 2676.83 ind 10 cm−2. Nematodes, harpacticoid copepods and foraminiferans were the most abundant among the 18 taxa registered. The highest densities of meiofauna were related to high levels of nitrogen and carbon (up to 0.14 μmol N g−1 and to 3.17 μmol C g−1) in stations affected by agro-industrial drainages and characterized by muddy sediments and slow tidal currents. The lowest densities of meiofauna were observed in stations with sandy sediments of low carbon and nitrogen content, located further away distant from agro-industrial discharges. Statistical analyses showed that high carbon content had a positive effect on copepod, foraminiferan, ostracod and nematode densities whereas the effect of nitrogen content was positive only for nematodes.