Distribution of Spawning and Nursery Grounds for Deep–water Red Shrimps in the Central Western Mediterranean Sea

Abstract

The presence of spawning and nursery grounds of Aristeids in the central western Mediterranean Sea were investigated using fishery-independent data (trawl surveys, 1994-2012). Spatial distributions were generated for mature animals and recruits, for both spring/summer and autumn data, using an inverse distance-weighted deterministic interpolation. The persistence index was used to identify stable spawning and nursery grounds in the Sardinian slope region for Aristaeomorpha foliacea and Aristeus antennatus. Areas of aggregation for recruits and mature females appear to be connected with important physical habitat features. The analysis also suggests a seasonal bathymetric distribution for nursery areas. The recruits of A. foliacea are located in the upper part of the continental slope (377-450 m) in spring/summer and reach greater depths (468-628 m) in autumn. For A. antennatus, for which nursery areas only emerge in autumn, there is presumably an opposite ontogenic migration, from deep sea to upper slope, during the summer (575-681 m). The results also indicate a partial overlap between the nursery and spawning grounds of both species. In this particular area, local environmental conditions such as upwelling events or the presence of canyons and seamounts seem to play an important role in their distribution. This study also generated relevant information on the spatial and temporal distribution of seasonal or persistent aggregations of spawners and recruits, providing scientific elements to suggest the protection of these important resources.

Condition and recruitment of Aristeus antennatus at great depths (to 2,300 m) in the Mediterranean: Relationship with environmental factors

“…We did not find higher reproductive condition for A. antennatus close to submarine canyons on the middle slope (between ca . 450–700 m) as previously indicated (off Catalonia: Sardà et al., ; off Sardinia: Palmas et al., ), in studies performed, mainly, over commercial grounds. Such studies suggested migrations by mating and spawning at the middle slope, i.e., over fishing grounds.…”

Seamounts as hot-spots of large pelagic aggregations

“…This is particularly relevant since most of the overlapping habitats areas are close to the coast and at relatively short distance from coastal fishing ports. This makes these seamounts particularly attractive for fishery exploitation (Sabatini et al, 2011;Palmas et al, 2015;Lauria et al, 2017) and thus easily subjected to one of the most commonly identified impacts on seamounts (Würtz and Rovere, 2015).…”

Ecological Role of Submarine Canyons and Need for Canyon Conservation: A Review

“…Suspension feeders and demersal planktivores likely benefit from these high concentrations of primary producers (Vetter et al, 2010). In Whittard Canyon (Celtic Margin of the NE Atlantic), accelerated currents increase the organic matter influx and therefore the availability of food compared to less active areas on the continental slope (Morris et al, 2013;Palmas et al, 2015). In the upper region of Whittard Canyon (∼700 m depth), a very dense assemblage of corals and large bivalves was observed associated with a nepheloid layer that might provide a significant amount of food (Johnson et al, 2013).…”