Search results for "Fish"

Sogdatawa ǝtumǝciusu

1934

Apskats par zivīm un zvejniecību nanaju (goldu) valodā.

Demographic effects of full vs. partial protection from harvesting: inference from an empirical before-after control-impact study on Atlantic cod

2015

Summary In recent years, marine protected areas (MPAs) excluding all or some fishing activities have become widely applied as a tool to rebuild marine ecosystems and fisheries, but still, our knowledge of the effects of MPAs on the demography of harvested populations remains scarce, especially in cases where partly protected areas are still supporting some fishing activities. Here, we investigated the influence of partial protection – excluding fixed gears such as gillnets and traps but still allowing a hook and line fishery – on the demography of Atlantic cod Gadus morhua along the Norwegian Skagerrak coast. To do so, we applied novel multi-event models to a 9-year data set containing both…

Enniatin B metabolites in liver and tissues of gilthead sea bream (Sparus aurata)

2016

Biomanipulating the drinking water reservoir of Estonia's capital city: Prospects for success

2008

The possibility of utilizing biomanipulation to improve the water quality of Tallinn's drinking water reservoir (Lake Ulemiste) was analysed on the basis of water quality data, test fishing by different methods, and earlier studies on aquatic plants, light climate and sediments. Eutrophic, polymictic Lake Ulemiste is characterized by a prevalence of high filamentous cyanobacteria biomass, rotifers in the zooplankton community, mature bream in the fish biomass, and a high density of planktivores (YOY perch). Several prerequisites for being a potential target for biomanipulation were identified, including (i) decreased external total phosphorus (TP) loading; and (ii) a sufficient stock of pis…

Can lake restoration by fish removal improve the status of profundal macroinvertebrate assemblages?

2013

Summary Removal of fish to restore lake pelagic food webs and water quality has been shown to increase the abundance of benthic invertebrates in shallow areas due to decreased predation pressure, while responses of profundal macroinvertebrate assemblages are less well documented. We used multivariate analyses and a Before-After-Control-Impact design to assess the impacts of fish removal (in total 101 000 kg of percid and cyprinid fish) on profundal macroinvertebrate species composition and abundance and ecological status in two basins of a eutrophic boreal lake. In the deeper main basin, macroinvertebrate community composition and classification of ecological status were not affected by fis…

The diversity, biomass and production of zooplankton in Lake Inarijärvi

1982

About 650 zooplankton samples were collected from Lake Inarijarvi in 1977–1979 from the littoral and pelagial zones of the lake. One hundred and twenty-three zooplankton taxa were found and most of them can be considered euplanktonic.

Artificial Reefs in the Gulf of Castellammare (North-West Sicily): A Case Study

2000

Most of the plans for fish stock replenishment recently undertaken in Sicily have focused on the Gulf of Castellammare. Reasons for choosing this biotope for a restocking plan include the size of the Gulf (300 km2), the importance and traditional role of its fisheries and the existence of information describing the local marine environment. The Gulf of Castellammare is the widest bay in Sicily and fishing has always played a major role in the local economy. Today income from fishing complements that from tourism.

Redds of brown trout in the deep channels of a hydroelectric power station

2019

Discrimination between stationary objects by the blind cave fishAnoptichthys jordani (Characidae)

1981

Blind Mexican cave fish were trained to discriminate between grids of vertical bars placed at various distances from each other. Discrimination was possible only if the freely swimming fish was allowed to glide past the grids in close proximity.

Parasitism of dolfinfhishes, <i>Coryphaena hippurus</i> and <i>Coryphaena equiselis</i>, in the western Mediterranean (Balear…

1999

A total of 648 dolphinfishes were examined for internal and external parasites in western Mediterranean (Balearic Islands) and central-eastern Atlantic (Canary Islands) waters in order to make a comparative study between the two areas. The specimens studied from the Mediterranean Sea was Coryphaena hippurus, with 62 large individuals captured from May to September and 497 juveniles captured from August to December. The specimens studied from the central-eastern Atlantic were 39 adult C. hippurus and 49 adult Coryphaena equiselis. Parasites were found in 70% of the fish examined, and represented a total of nine endoparasitic taxa: six digeneans (Class Trematoda, Subclass Digenea; Dinurus tor…