Zooplankton Abundance and Diversity in the Tropical and Subtropical Ocean

Abstract

The abundance and composition of zooplankton down to 3000 m depth was studied in the subtropical and tropical latitudes across the Atlantic, Pacific and Indian Oceans (35 °N–40 °S). Samples were collected from December 2010 to June 2011 during the Malaspina Circumnavigation Expedition. Usually, low abundances were observed with the highest values found in the North Pacific Ocean, Benguela, and off Mauritania, and the lowest in the South Pacific Ocean. No significant differences in abundance and zooplankton composition were found among oceans, with depth being consistently the most important factor affecting their distribution. Each depth strata were inhabited by distinct copepod assemblages, which significantly differed among the strata. The contribution of copepods to the zooplankton community increased with the depth although, as expected, their abundance strongly decreased. Among the copepods, 265 species were identified but 85% were rare and contributed less than 1% in abundance. Clausocalanus furcatus and Nannocalanus minor dominated the epipelagic strata. Pleuromamma abdominalis and Lucicutia clausi were of importance in the mesopelagic layer, and Pareucalanus, Triconia, Conaea and Metridia brevicauda in the bathypelagic layer. Our results provide a global-scale assessment of copepod biodiversity and distribution, providing a contemporary benchmark to follow future ocean changes at low latitudes.

Proteomic fingerprinting facilitates biodiversity assessments in understudied ecosystems: A case study on integrated taxonomy of deep sea copepods

“…The biodiversity assessment based on proteomic fingerprints, validated with morphological identification and COI sequence analysis, estimated a taxonomic richness of 79 species and, as a result of low within‐species abundance, a diversity of 3.5. This diversity is comparable to the highest diversity estimates of calanoid copepods in pelagic studies (e.g., Fernández de Puelles et al, 2019; Hwang et al, 2009). Information on copepod diversity and species richness in the pelagic habitat of the tropical South Atlantic is sparse and almost lacking for benthopelagic layers.…”

Three‐dimensional distribution of mesoplankton assemblages in the Central Atlantic

“…No clear depth‐related trend was visible in the distribution of either ES‐100 or the Shannon–Wiener index. This outcome contradicts the results of some previous investigations that suggested a significant increase in species numbers (and, hence, biodiversity) in the mesopelagic layer (e.g., Bucklin et al., 2010; Fernández de Puelles et al., 2019; Hirai et al., 2020). Possible reasons for this contradiction are a lower taxonomical resolution of mesoplankton in our study (mostly at the generic level) and a restricted size range of analysed animals (only mesoplankton).…”

“…In the Central Atlantic, however, no sharp hydrological gradients are present except the main thermocline (Broecker & Takahashi, 1981; Kolterman et al, 2011). Horizontal changes in the zooplankton structure in these low‐gradient zones occur, therefore, over larger areas and are likely more dependent on currents and primary production than on hydrological fronts (Fernández de Puelles et al., 2019; Longhurst, 2007; Piontkovski et al., 2003; Vereshchaka et al, 2016; Villarino et al., 2018).…”

Abundance and Structure of the Zooplankton Community During a Post-eruptive Process: The Case of the Submarine Volcano Tagoro (El Hierro; Canary Islands), 2013-2018

“…Overall, the copepod taxa identified during the 6 years studied were close to the historical data described in the epipelagic water of the nearby island of Tenerife and El Hierro (Corral, 1970;Fernández de Puelles, 1977, 1986, where the dominant copepod genera were also Oncaea, Oithona, Clausocalanus, and Paracalanus. All the dominant species that are quantitatively important in El Hierro in more or less constant numbers are considered also cosmopolitan and ubiquitous in waters of the large subtropical open ocean (Fernández de Puelles et al, 2019). Cyclopoids as well as Clausocalanus and Paracalanus were usually characteristic of oligotrophic areas (Bucklin et al, 2010).…”

“…Copepods have been able to colonize all extreme aquatic habitats, including the deep ocean (Fernández de Puelles et al, 2019) as well as the active hydrothermal vents (Dahms and Hwang, 2013). Compared to coastal waters, copepods at venting and volcanic areas have to cope with hydrodynamic stress more than in deeper water (Nielsen et al, 2017), tending to produce a higher abundance and a lower diversity (Tarasov, 2006) as could be the case in our study.…”