Gap analysis on the biology of Mediterranean marine fishes

Abstract

We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length-weight relationships, as well as the economy of scientific sampling (using the entire catch to acquire data on as many biological characteristics as possible) are discussed.

Anecdotal information on dolphin-fisheries interactions based on empirical knowledge of fishers in the northeastern Mediterranean Sea

“…Interactions between dolphins and coastal fisheries is a 'hot' issue of increasing concern in the Mediterranean Sea, with economic, social and ethical implications that further complicate fisheries management. Moreover, apart from important fisheries data that are also poor in the Mediterranean (Dimarchopoulou et al 2017), it is imperative to improve scientific knowledge on dolphin population dynamics and behaviour patterns, especially with respect to fisheries. Many marine mammal−fisheries interaction studies, which usually require extensive human resources and funding and are often spatiotemporally constrained, rely solely on information derived from fishers or are combined with field observations (López et al 2003).…”

Catching the big picture of the Mediterranean Sea biodiversity with an end-to-end model of climate and fishing impacts

“…Mediterranean basin and across Geographical Sub-Areas (GSAs), and the potential cascading 752 effects on food webs and ecosystem services. We could clearly take advantage of existing 753 historical collections of biological and ecological data that were assembled in various databases 754 Sea despite some gaps can be pointed out, mostly concerning for the fish species in the southern 763 part of the basin (Dimarchopoulou et al, 2017). There is, for instance, no biological information 764 for as many as 43 % of the Mediterranean fish species (Dimarchopoulou et al, 2017).…”

“…We could clearly take advantage of existing 753 historical collections of biological and ecological data that were assembled in various databases 754 Sea despite some gaps can be pointed out, mostly concerning for the fish species in the southern 763 part of the basin (Dimarchopoulou et al, 2017). There is, for instance, no biological information 764 for as many as 43 % of the Mediterranean fish species (Dimarchopoulou et al, 2017). The lack of 765 biological and ecological data for a large number of species as well as the quality of commercial 766 fisheries data, especially in the southern and eastern parts of the Mediterranean Sea, are 767 hindrances to reliable stock assessments, to the development of more integrated ecosystem 768 models, and thus to the implementation of an effective ecosystem-based management to achieve 769 good environmental status in the Mediterranean Sea (Coll et al, 2013;Piroddi et al, 2015aPiroddi et al, , 2017.…”

Artificial upward trends in Greek marine landings: a case of presentist bias in European fisheries

“…In Greek waters, a fisheries data-poor area [4], the initial [5] and recent catch reconstructions [6] revealed several discrepancies, inconsistencies and dataset discontinuities prior to 1982 and an unreported catch that may exceed 30% of the officially reported landings. However, despite those inconsistencies and biases that are confined to the earlier years of the dataset (1970-1981) and several aggregations to higher taxonomic groups [7], the modus operandi of the Greek statistical authorities remained the same between 1982 and 2015 [8, 9].…”