Copepod distribution and production in a Mid-Atlantic Ridge archipelago

Abstract

The Saint Peter and Saint Paul Archipelago (SPSPA) are located close to the Equator in the Atlantic Ocean. The aim of this study was to assess the spatial variations in the copepod community abundance, and the biomass and production patterns of the three most abundant calanoid species in the SPSPA. Plankton samples were collected with a 300 µm mesh size net along four transects (north, east, south and west of the SPSPA), with four stations plotted in each transect. All transects exhibited a tendency toward a decrease in copepod density with increasing distance from the SPSPA, statistically proved in the North. Density varied from 3.33 to 182.18 ind.m -3 , and differences were also found between the first perimeter (first circular distance band) and the others. The total biomass varied from 15.25 to 524.50 10 -3 mg C m -3 and production from 1.19 to 22.04 10 -3 mg C m -3 d -1 . The biomass and production of Undinula vulgaris (Dana, 1849), Acrocalanus longicornis Giesbrecht, 1888 and Calocalanus pavo (Dana, 1849) showed differences between some transects. A trend of declining biodiversity and production with increasing distance from archipelago was observed, suggesting that even small features like the SPSPA can affect the copepod community in tropical oligotrophic oceanic areas.

When Bergmann's rule fails: evidences of environmental selection pressures shaping phenotypic diversification in a widespread seabird

“…This process allows for the retention of nutrients from allochthonous or autochthonous sources (e.g. seabird guano), making the biomass and zooplankton productivity in the vicinity of SPSP similar to those observed around seamounts (Mullineaux and Mills , Melo et al ). A pattern of higher productivity and presence of relatively colder waters closer to the surface is more pronounced around SPSP than nearby tropical islands sampled for this study, i.e.…”

Zooplankton From a Reef System Under the Influence of the Amazon River Plume

“…In most tropical and subtropical marine waters, the zooplankton community is dominated by copepods, which occupy key trophic positions ( Neumann-Leitão et al, 2008 ; Melo P.A.M.C. et al, 2014 ; Costalago et al, 2015 ).…”

Connectivity Between Coastal and Oceanic Zooplankton From Rio Grande do Norte in the Tropical Western Atlantic

“…There is a reported relation between U. vulgaris and coastal areas due to its occurrence in neritic environs; U. vulgaris exhibits a high abundance in many inshore plankton hauls in the surface layer (Razouls et al, 2005). However, U. vulgaris dominated among copepods in samples from oceanic provinces in the economic exclusive zone (EEZ) of Northeastern Brazil (Cavalcanti and Larrazábal, 2004;Melo et al, 2014;Campelo et al, 2018). In our study, U. vulgaris was also abundant at young stages under oceanic influence, which suggested that it also inhabits oceanic regions with an epi-mesopelagic distribution.…”

“…In oligotrophic areas, species occur with smaller sizes and in developmental stages that are important in planktonic communities and these areas are dominated by microbial components (Calbet et al, 2001;Turner, 2004;Calbet, 2008). Small-sized copepods are a pivotal link between the classical and microbial food webs (Nakamura and Turner, 1997;Melo et al, 2014); they present a much higher growth rate (Peterson et al, 1991;Hopcroft et al, 1998) and influence the effectiveness of the trophic connection between primary producers/protozooplankton and larger species (Zervoudaki et al, 2007). One of the most oligotrophic oceans in the world is the Southwest Atlantic Ocean (Andrade et al, 2007); and, Dias et al (2015) mention that oligotrophic areas present higher production than formerly supposed and have an extraordinary amount of biotic complexity, encompassing nearly 75% of marine surfaces.…”