Holothurian Fisheries in the Hellenic Seas: Seeking for Sustainability

Abstract

In Mediterranean, the exploitation and exportation of holothurians as food is increasing during the last 25 years, with Turkey and Greece as leading countries. In Greece, the fishery is expanding by the development of two métiers; however, official monitoring is missing, creating concerns on the future viability of the industry. To evaluate the status and future perspectives of holothurian fisheries, an extensive field survey has been completed (May 2019–July 2021) covering 162 sites dispersed in the Hellenic Seas. Field data included the assessment of the abundance of holothurians (via 100 m transect replicates), and catch per unit of effort (CNPUE and CBPUE, based on 10-min commercial fishing practices). H. tubulosa, H. poli, H. mammata and H. sanctori were fished in 41.35% of the surveyed stations. H. poli (CNPUE 168 specimens, CBPUE 22.24 kg) and H. tubulosa (CNPUE 127 specimens, CBPUE14.51 kg) were the most common species, forming locally dense populations. Mean annual catch was 275 metric tons (2016–2021) according to the processing of the units’ data; 62% of the production was made by H. tubulosa and 38% by H. poli. Our results suggest the existence of exploitable grounds in the north Aegean, the central Cyclades, and the north Dodecanese, according to the prevalent environmental conditions (organic load) and fishing pressure.

Oceanographic Research in the Thermaikos Gulf: A Review over Five Decades

“…This increased diversity of the benthic invertebrate fauna emerges from the relevant diversity in habitat types (see Section 4.5.1) and from the extensive taxonomic studies focusing in particular on the phylum Mollusca [156][157][158][159]. Among the reported invertebrate species, some are commercially exploited, such as the clams Venus verrucosa and Callista chione, the scallops Pecten jacobaeus and Flexopecten spp., the prawns Penaus kerathurus and Parapenaeus longirostris, the mud and mantis shrimps Upogebia tipica and Squilla mantis, the crabs Callinectes sapidus and Maja squinado, and the sea cucumbers Holothuria tubulosa and H. poli [160][161][162][163], raising concerns regarding the future viability of natural stocks and habitats. Other species, however, face direct threats, such as the endangered corals Crassophyllum thessalonicae (Figure 12a) and Cladocora caespitosa (Figure 12b) and the critically endangered fan mussel Pinna nobilis (Figure 12c).…”

Microplastics pollution in genetically connected populations of Holothuria forskali from south Bay of Biscay

“…Systematic holothurian fisheries started in Turkey in 1996, followed by Greece, Spain, France, and Italy, and focus on a few species (Hamel and Mercier, 2008;Gonzaĺez-Wangüemert et al, 2014). FAO has just started to officially record sea cucumber landings per country in the Mediterranean fishing area (i.e., FAO 37), where they were previously undocumented (Vafidis and Chryssanthi, 2023). Currently, FAO recommends size and gear limitations (https://www.fao.org/3/i1384e/i1384e05a.pdf) that are followed by different countries.…”

Estimating age and growth parameters for three commercial NE-Atlantic sea cucumbers, Holothuria mammata, H. forskali and H. arguinensis, in a marine protected area

“…As a result of local stock depletion and closure of some regional and national fisheries (Purcell, 2014), the exploitation of natural stocks expanded to other areas endangering additional species (Purcell et al, 2013;Eriksson and Clarke, 2015). In the North-eastern Atlantic and the Mediterranean Sea, several sea cucumber species, new to the international trade markets, are now targeted for directed fisheries (Gonzaĺez-Wangüemert et al, 2018;Vafidis and Antoniadou, 2023). The absence of time-series data on landings, biometry, and the density of natural holothurian stocks presents a significant obstacle to assess the population's health.…”

“…However, in some regions, a decrease in density, abundance, genetic diversity, loss of the largest size classes and even local stock depletion are evidence of overexploitation due to fishing pressure (some occurring illegally; Gonzaĺez-Wangüemert et al, 2014;Gonzaĺez-Wangüemert et al, 2018). Holothuria (Holothuria) mammata Grube, 1840 and Holothuria (Holothuria) arguinensis Koehler and Vaney 1906 are commercially relevant and targeted species in the in the NE-Atlantic and Mediterranean (Gonzaĺez-Wangüemert et al, 2014;Gonzaĺez-Wangüemert et al, 2018;Dereli and Aydın, 2021;Vafidis and Antoniadou, 2023), while Holothuria (Panningothuria) forskali Delle Chiaje, 1824 has seen an increasing interest (Gonzaĺez-Wangüemert et al, 2016) with values going for over $ 100 USD per dry kg on the market (Sousa et al, 2020). Illegal captures of sea cucumbers, mainly H. arguinensis and H. mammata, have increased for the past years with populations showing local signs of overexploitation (Gonzaĺez-Wangüemert et al, 2018).…”