Search results for "Aquaculture. Fisheries. Angling"
showing 10 items of 43 documents
Introduced alien signal crayfish (Pacifastacus leniusculus) in Finland : uncontrollable expansion despite numerous crayfisheries strategies
2018
In Finland, massive signal crayfish introductions started towards the end of 1980s, with an estimated total of 2.2 million signal crayfish been stocked before year 2016. During that period, Finnish fisheries authorities have implemented three national management strategies setting guidelines for the crayfish introductions. The main aims of the strategies have been conservation of native noble crayfish stocks and a controlled spreading of the alien signal crayfish within a designated region. In this study, we report the current distribution of signal crayfish in Finland in comparison to the guidelines set in these three national strategies. The present distribution area of the signal crayfis…
Are the effects of an invasive crayfish on lake littoral macroinvertebrate communities consistent over time?
2016
Management of invasive species requires assessment of their effects on recipient ecosystems. However, impact assessment of invasive species commonly lacks a long-term perspective which can potentially lead to false conclusions. We examined the effects of the invasive signal crayfish (Pacifastacus leniusculus Dana) on the stony littoral macroinvertebrate communities of a large boreal lake and assessed the extent to which the patterns observed in previous short-term studies were stable over time. We used temporal macroinvertebrate data collected in five consecutive years from a site with a well-established crayfish population, a site with no crayfish and a site where crayfish had been recentl…
The trophic position of the Atlantic blue crab Callinectes sapidus Rathbun 1896 in the food web of Parila Lagoon (South Eastern Adriatic, Croatia): A…
2016
The Atlantic blue crab Callinectes sapidus is to date widely distributed in the Mediterranean Sea, where is recognized as an Invasive Alien Species. Noticeably, while records of its occurrence are increasing, quantitative information on its functional role in the benthic food webs of invaded coastal habitats are scarce. Here, carbon and nitrogen isotopic signatures were measured in C. sapidus and other representative taxa of the benthic flora and fauna sampled in summer in the Parila Lagoon, a coastal basin located in the Neretva River estuary area (Croatia). d 15 N values of individual blue crab specimens were used to calculate their trophic position (TP) , using the filter feeder mussel M…
Effectiveness of Posidonia oceanica biotic indices for assessing the ecological status of coastal waters in the Saronikos Gulf (Aegean Sea, Eastern M…
2017
Biotic indices are considered key assessment tools in most national and European policies aimed at improving the quality of coastal waters. At present, several Water Framework Directive (WFD)-compliant biotic indices based on the marine angiosperm Posidonia oceanica have been developed and applied in the Mediterranean Sea. In this study, we investigated the effectiveness of four different P. oceanica indices (POMI, PREI, Valencian CS, and BiPo) in evaluating the ecological status of coastal waters in a case study area of Greece. The evaluation, comparison, and validation of the Ecological Status Class (ESC) assessments obtained by each index were based on a set of eight common sites that en…
Modelling the effects of more selective trawl nets on the productivity of European hake (Merluccius merluccius) and deep-water rose shrimp (Parapenae…
2018
Single-species Gadget models were used to assess the effects of using a sorting grid mounted on the traditional trawl net used by Sicilian trawlers to exploit the deep-water rose shrimp in the Strait of Sicily. The main commercial by-catch species of this fleet is the European hake (Merluccius merluccius), often caught at sizes well below the minimum conservation reference size. Selectivity curves based on the results of an experimental survey carried out in the area using a commercial trawler equipped with an ad hoc-designed sorting grid were incorporated into single-species Gadget models to forecast the effects of changing fishery selectivity on the performance of the two stocks in terms …
Maristem stem cells of marine/aquatic invertebrates: from basic research to innovative applications
2018
The “stem cells” discipline represents one of the most dynamic areas in biomedicine. While adult marine/aquatic invertebrate stem cell (MISC) biology is of prime research and medical interest, studies on stem cells from organisms outside the classical vertebrate (e.g., human, mouse, and zebrafish) and invertebrate (e.g., Drosophila, Caenorhabditis) models have not been pursued vigorously. Marine/aquatic invertebrates constitute the largest biodiversity and the widest phylogenetic radiation on Earth, from morphologically simple organisms (e.g., sponges, cnidarians), to the more complex mollusks, crustaceans, echinoderms, and protochordates. These organisms contain a kaleidoscope of MISC-type…
Solapamiento del nicho trófico en un área de cría en la costa portuguesa
2002
The diets and the trophic niche overlap between seven flatfish species were studied in a coastal nursery adjoining to the Tagus estuary (Portugal). Fish were sampled monthly, from March to November 1999, using a beach seine. Arnoglossus imperialis (Rafinesque, 1810), Arnoglossus laterna (Walbaum, 1792) and Arnoglossus thori Kyle, 1913, fed mainly on crustaceans. The diets of Buglossidium luteum (Risso, 1810) and Dicologoglossa cuneata (Moreau, 1881) were mainly composed of Bivalvia and Polychaeta, while for Scophthalmus rhombus (Linnaeus, 1758) the main food items were Mysidacea and Teleostei. The diet of Pegusa lascaris (Risso, 1810) was mainly composed by Cumacea, Bivalvia, Decapoda and A…
Southern Ocean areas of endemism: a reanalysis using benthic hydroids (Cnidaria, Hydrozoa)
2013
The biogeographic history of the Southern Ocean (SO) fauna is complex and poorly studied, especially the areas of endemism. We reanalyzed the data of Marques & Peña Cantero (2010), along with other geographical records of endemic benthic hydroids below 45°S. A Parsimony Analysis of Endemicity (PAE) based on 5° latitude by 5° longitude matrix with 61 species resulted in eight areas of endemism. We discuss these results in the context of different hypotheses of the evolution of the SO fauna and previously proposed biogeography patterns.
Artificial dam lakes as suitable habitats for exotic invertebrates: Ostracoda ecology and distribution in reservoirs of the Eastern Iberian Peninsula
2014
Reservoirs are the most common deep lakes in Spain, as a consequence of water needs and dry climate. Although these aquatic systems can play an important ecological role in such an area with few large natural lakes, they can also provide new habitats for exotic species, which can colonize ecosystems that native species have not explored yet. Here we present our results for a biannual survey of the ostracod fauna from 24 reservoirs in Xuquer River basin. We check which variables affect ostracod presence, test for differences between winter and summer assemblages, and compare our data with previous available ostracod records from the same river drainage network. Our results reveal that ostrac…
Trawling disturbance effects on the trophic ecology of two co-generic Astropectinid species
2015
Physical disturbance by trawling can have both negative and positive effects on populations of scavenging benthic organisms. In the present study the impact of fishing activity on feeding behaviour of the two Astropectinids, Astropecten bispinosus and A. irregularis , was assessed based on stomach contents analysis. The study was carried out along trawled seabed highlighting the positive response of the two facultative scavengers to carrion generated by trawl disturbance. Furthermore, there was greater food specialization in areas that were more heavily exploited by trawling. This specialisation could be linked to the availability of certain prey that results from the passage of fishing gea…