Vol. 53, 2014

A new comparative study of zooplankton from oceanic, shelf and harbour waters, south-east coast, Jamaica

Kristoffer A Lue and Mona K Webber*

Department of Life Sciences, University of the West Indies, Mona Campus, 4 Anguilla Close, Kingston 7, Jamaica

Abstract
Background: Zooplankton samples were collected fortnightly from four locations representing oceanic, shelf and harbour waters off Kingston, Jamaica in 2004, approximately 40 years after a similar study was concluded in 1964. The present sampling was conducted using vertical hauls with plankton nets of three different mesh sizes: 64, 200 and 600 μm between April and November 2004.
Results: Mean zooplankton abundances across the stations ranged from a maximum (5,858.5 individuals m⁻3) at Harbour Shoal Beacon, mouth of Kingston Harbour, to a minimum (2,124.2 individuals m⁻3) at California Bank, an offshore bank. One hundred forty-seven different taxa of zooplankton were identified during this study. Eighty-one taxa were identified from Harbour Shoal Beacon (HSB), 106 from South-East Cay (SEC), 114 from the shelf-edge station, called Windward Edge (WE), and 94 from California Bank (CB). The pattern obtained from the clustering of stations using percent similarity coefficient (PSC) and Jaccard community coefficient (JCC) showed the presence of two distinct groups of stations: one with HSB and the other containing all other stations. The abundance of individual species was also examined for their potential to characterize the different water masses. As found 40 years ago, Lucifer faxoni and Penilia avirostris were indicators of eutrophic Kingston Harbour waters, while Microsetella norvegica and Farranula carinata were identified as indicators of offshore waters. Zooplankton parameters across the area clearly distinguished the eutrophic Kingston Harbour waters from the shelf and offshore sites but could not differentiate between the mesotrophic shelf and the offshore bank. Larval forms were numerically dominant across all stations with copepod nauplii, fish eggs and echinoderm larvae being major constituents.
Conclusions: The zooplankton communities in the harbour, shelf and offshore areas of Jamaica's south-east coast still show significant spatial differences; however, the zooplankton community at the offshore bank was more similar to the shelf than was expected. Such banks although located offshore, receive enrichment due to associated circulation patterns. Therefore, they should not be considered oligotrophic and based on the zooplankton community distributionwould be more accurately classified as mesotrophic.

Key words: Zooplankton; Kingston Harbour; Shelf; Offshore bank.

*Correspondence: E-mail: mona.webber@uwimona.edu.jm