A comparative study of marine zooplankton communities in the Tangier and M’Diq (Gibraltar strait) regions

Abstract

-This comparative study of mesozooplankton communities in the Tangier (Atlantic) and M'Diq (Mediterranean) regions was carried out in March, May and December 2006 and in May, July and November 2007. In both sectors, the zooplankton is mainly dominated by copepods, which represent 93% in Tangier and 87% in M'Diq, with respectively 85 species in 24 families and 81 divided into 22 families. Spatio-temporal analysis of Copepod specific richness data revealed highest values occurring in both areas during December 2006 and November 2007 with 36 and 30 species respectively. During other seasons, specific richness did not generally exceed 25 species. However, irrespective of area, the composition of the Copepoda population was usually dominated by Paracalanus parvus and Oncaea venusta. In terms of total density, the Atlantic is greater than the Mediterranean sector with a maximum density of 1093 ind.m −3 and 796 ind.m −3 , respectively, recorded in July and May, 2007. The Shannon diversity index was calculated and indicated that the Copepod community is more stable and balanced in the Tangier region compared to the M'Diq area, and in 2007 compared to 2006. Moreover, seasonal variation is more marked in the Atlantic than in the Mediterranean area and in both sectors, the autumn season is characterized by a low productivity but high specific diversity. Key words

The Atlantic–Mediterranean ecological connection: a study on decapod larval communities

“…Similarities (e.g. Madin, 1991;Champalbert, 1996;Xavier & Soest, 2012;Zaafa et al, 2014) and differences (e.g. Triantafyllidis et al, 2005) have been reported between Atlantic and Mediterranean communities for zooplankton and decapods.…”

Diversity and Distribution of Mesozooplankton in the Coastal Southwestern Mediterranean Alboran Sea, during Summer: What Are the Driving Factors?

“…Several studies involving zooplankton sampling with mesh sizes ranging from 147 to 200 microns showed the dominance of copepods in different Mediterranean ecosystems greater than 60% in the eastern and western Alboran Sea [57][58][59]. The dominance of copepods was previously demonstrated in the Moroccan Mediterranean [22,30] and in the Moroccan Atlantic coasts [36,37,60,61], as well as in the Canary Current Large Marine Ecosystem (CCLME) region [38]. Although samples were collected in these areas using nets with different mesh sizes, copepod dominance remains significant and consistent across all these zones.…”

“…Studies published on the diversity and distribution of zooplankton along the Moroccan Mediterranean coast are very limited [22,29,30]. This coast has yet to be explored when compared with the Atlantic Coast [31][32][33][34][35][36][37][38].…”

Copepod community along the Mediterranean coast of Morocco (Southwestern Alboran Sea) during spring

“…The inflow of Atlantic water, may explain the presence of some rare species (Youssara & Gaudy, 2001;Zaafa et al, 2012). As an example, Centropages chierchiae was recorded only in a few stations.…”

“…In the Mediterranean Sea, its distribution is limited to the western part (Razouls et al, 2005(Razouls et al, -2016 influenced by the Atlantic flow. According to 2006-2007 data, among the 103 species recorded at two transects on both sides of the Gibraltar Strait, 61.2% were common in both sectors, whereas 21.4% and 17.5% were endemic to the Atlantic Ocean and the Mediterranean Sea respectively (Zaafa et al, 2012).…”