Die Situation der Makrelen- und Stöckerbestände. Der deutsche Beitrag zur internationalen Bestandsabschätzung

The question has not yet been completely solved whether or not the mackerel and horse mackerel stocks in the waters from the Bay of Biscay to the Atlantic off the Norwegian coast are independent unit stocks or must be regarded rather as one stock with distinct stock components. The stock definition, however, is the basis for fishery management and is fundamental for the exploitation of the stocks. For this reason the extensive mackerel and horse mackerel egg survey carried out in 1998, is of high importance and significance for the fishery management of the two species. The survey has begun in January in Iberian waters and will eventually end in the autumn north of Scotland. To cope with this task research vessels of eight European nations are participating.

Lage und Entwicklung der Fischereiressources in Hinblick auf deutsche Fischereiinteressen

The northern European fish stocks are assessed annually by ICES working groups. The results are evaluated biannually in two meetings of the Advisory Committee for Fisheries Management (ACFM) at ICES. Based on the working group assessments, ACFM formulates an advice for fisheries management and suggests a total allowable catch (TAC) which is based strictly on biological grounds. The summaries of the state of some selected stocks which are given here, are derived from the ACFM advice, formulated during the most recent May 1998 meeting. For many of the fish stocks the precautionary approach is still in the process of implementation, and only for some of them the management and target reference points have been fully defined.

Lage und Entwicklung der Fischereiressourcen im Hinblick auf deutsche Fischereiinteressen: Neuste Bestandsabschätzung des ACFM

The North European fish stocks are assessed annually by ICES working groups. The results are evaluated biannually in two meetings of the Advisory Committee for Fisheries Management (ACFM) at ICES. Based on the working group assessments, ACFM formulates an advice for fisheries management and suggests a total allowable catch (TAC) which is based strictly on biological grounds. The summaries of the state of some selected stocks which are given here, are derived from the ACFM advice, formulated during the most recent Oktober 1998 meeting. For many of the fish stocks the precautionary approach is still in the process of implementation, however for most of them the management and target reference points have been fully defined by now.

Die Entwicklung wichtiger Fischbestände in der Nordsee und im Nordatlantik. Ergebnisse der Herbstsitzung des Advisory Committees for Fishery Management des internationalen Rates für Meeresforschung

The October meeting of the ACFM of ICES gave advice for a number of North-Atlantic fish stocks. The results of the most important stocks are given here from the perspective of German fishery management. The are chiefly North Sea plaice and sole, for which a reduction of 25 % of the fishing mortality (F) is recommended for 1998, North Sea saithe (minus 20 % in F), while North Sea cod is in the process of recovery and North Sea haddock is inside safe biological limits. The mackerel stock of the North Sea has not yet recovered, while the western mackerel stock as an entity has stabilised at a level of about 2.3 million t.

Deutscher Beitrag zum internationalen Makrelen(Scomber scombrus) und Stöcker- (Trachurus trachurus) Eier-Survey

Based on the results from egg and larvae surveys, mackerel and horse mackerel are thought to form three more or less distinct stocks each in the North Sea and in the waters west of the British Isles. These are firstly the southern stocks in the southern part of the English Channel, Celtic Sea and Bay of Biscay, secondly the North Sea and finally the western stocks of both species, loeated between the Shetlands and southern Norway. It is argued here that in view of the high mobility and the extended seasonal migrations of both species a c1ear separation of the stocks can hardly be maintained. In this context the results of the 1995 mackerel and horse mackerel egg survey to the southern spawning location is presented.

Das europäisches Netzwerk zur Koordination der Altersbestimmung bei Fischen: European Fish Ageing Network (EFAN)

Financial support is going to be applied for from the European Commission in order to establish the European Fish Ageing Network (EFAN). The project, which was planned and initiated from Norway (Floedevigen) is supposed to be a concerted action from 14 European Countries involving about 35 institutions. The primary aim of the network is to coordinate the research in age reading, especially the improvement of data bases for reference material, the transformation of research (e.g. daily ring formation in otoliths) to each interested reader. Moreover, the applied financial support is supposed to be preliminary spent for travel of researcher and technicians to other institutes where the same fish species are aged. Reference material is supposed to be sent to the institutes for check-reading. Specific workshops will be held in cases where heterogeneous results occur from check-reading the reference material.

Internationaler Rotbarschsurvey auf den ozeanischen Sebastes mentella in der Irminger See unter isländischer, deutscher und russischer Beteiligung

A hydroacoustic survey on the oceanic redfish (oceanic Sebastes mentella) in the Irminger Sea and adjacent waters South and East of Greenland was carried out by Iceland, Germany and Russia. During this, about 250 000 nm2 were covered. The acoustic assessment yielded a stock size of approximately 1.6 x 10(6) tonnes or 2.6 x 10(9) individuals. This however, is considered to be an underestimation of the stock, as a result of partial mixing of the stock with the scattering layer. The oceanic redfish concentrations were densest at 200-300 m depth, mainly within temperatures of 3.5 °C to 5 °C. 61 % of the stock were males at an average length of 36 cm and an average weight of 582 g.

Deutsche und internationale Bestandsuntersuchungen an Heringen mit hydroakustischen Methoden

The international hydroacoustic herring survey in the North Sea is carried out since the early eighties with Dutch, Scottish, Danish und Norwegian contribution. Since 1994 Germany also participates in this survey on a regular basis and has taken over a sector in the easter part between the Dogger Bank and the Danish coast. This area is known for the abundance of chiefly juvenile herring and sprat. During the 1995 cruise some 420000 t of herring were found here, most of them being juveniles of age group I. Analyses of plankton hauls showed that planktonic echos were not caused by juvenile herring, instead the echos were apparently produced by small pelagic gastropodes of the genus Spiratella.

Effects of harvesting methods on sustainability of a bay scallop fishery: dredging uproots seagrass and displaces recruits

Fishing is widely recognized to have profound effects on estuarine and marine ecosystems (Hammer and Jansson, 1993; Dayton et al., 1995). Intense commercial and recreational harvest of valuable species can result in population collapses of target and nontarget species (Botsford et al., 1997; Pauly et al., 1998; Collie et al. 2000; Jackson et al., 2001). Fishing gear, such as trawls and dredges, that are dragged over the seafloor inflict damage to the benthic habitat (Dayton et al., 1995; Engel and Kvitek, 1995; Jennings and Kaiser, 1998; Watling and Norse, 1998). As the growing human population, over-capitalization, and increasing government subsidies of fishing place increasing pressures on marine resources (Myers, 1997), a clear understanding of the mechanisms by which fishing affects coastal systems is required to craft sustainable fisheries management.

A Whale of a Deception

In late October of 1966, an imposing ship steamed quietly through the placid waters of the Suez Canal. Clad in drab industrial gray, and flying a Soviet hammer and sickle flag at her masthead, the vessel was accompanied by a large fleet of smaller craft. Any observer able to decipher Cyrillic script could have read, in rusting metallic letters on her bow, the name Sovetskaya Ukraina. The more experienced would perhaps have identified her as a whaling factory ship, traveling with her attendant fleet of catcher boats and scouting vessels on a transit that would take them south into the Red Sea and beyond.

Die vertikale Verteilung von Heringslarven im Greifswalder Bodden

Kurzfassung Im Rahmen einer Bachelorarbeit wurde untersucht, ob die Larven des frühjahrslaichenden Herings der westlichen Ostsee im Greifswalder Bodden eine inhomogene vertikale Verteilung aufweisen, da in bisherigen Studien aufgrund der niedrigen Gewässertiefe des Boddens von hydrografischer Durchmischung und somit homogener Ichthyoplanktonverteilung ausgegangen wurde. Dazu wurden zwei Nullhypothesen überprüft, eine, die annimmt, dass Heringslarven allgemein im Greifswalder Bodden homogen verteilt sind, eine zweite, nach der auch verschiedenen Längenklassen der Heringe homogen verteilt sind. Die Proben, die Mitte April an drei verschiedenen Stationen im Greifswalder Bodden genommen wurden, zeigten signifikante Unterschiede der Larvenabundanzen allgemein zwischen den beprobten Tiefenstufen als auch der Längenklassen zwischen den Tiefenstufen, sodass beide Nullhypothesen abzulehnen sind. Eine homogene Verteilung der Heringslarven kann ausgeschlossen werden. Abstract Larvae of the Western Baltic Spring Spawning Herring were sampled in the Greifswalder Bodden in the course of a Bachelor Thesis to investigate whether they are inhomogeneously vertically distributed. Previous research assumed homogeneous vertical distribution because of the shallowness of the Greifswalder Bodden due to hydrographical mixing of the water and the ichthyoplankton. Two null hypotheses were tested, one which presumes even vertical distribution of the herring larvae and another which presumes even vertical distribution within different length classes in the Greifswalder Bodden. Sampling took place at three different stations in the Greifswalder Bodden during April and results showed significant differences of the larvae abundances between the sampled depths and also significant differences of the length classes between the sampled depths. Therefore both null hypotheses can be rejected and a homogeneous vertical distribution of the herring larvae in the Greifswalder Bodden can be excluded.

Maryland commercial fisheries statistics, 1944-1945

This report presents a statistical analyses of the "fin" fisheries, as distinguished from the crab and oyster fisheries of Maryland, for 1944 and 1945. Comparative data on the catch by species, by area, and by gear, based principally on daily reports from the fishermen, are available for the first time as a result of a comprehensive statistical survey made by the Department of Research and Eduction to determine the results of the new management plan for the fisheries, referred to as the Maryland Management Plan. With the initiation in 1941 of a new system of fishery management in the State, a conservation plan based on the principle of stabilized fishing effort, it became obvious that a more accurate catch record system was needed for the proper administration of the program. The Management Plan stabilized the number of licensed fishermen at the 1939-1940 level, and provided for controlled expansion of the fishery to take place only when and where the industry warranted it as a result of increased fish populations. The text of the Plan may be found in Article 39, Section 60, Annotated Code of Maryland, 1943 Supplement. Publications 1, 2, 5, and 6 of the Educational Series of the Department of Research and Education explain the operating principles and the application of same to two important Maryland species, the shad and the rock or striped bass. Ocean fishery records only cover monthly gross landings.