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Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1987-2011, compiled from statistics about ICCAT fishery region L6

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1973-2011, compiled from statistics about ICCAT fishery region L2

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1980-2009, compiled from statistics about ICCAT fishery region L9

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1956-2010, compiled from the International Commission for the Conservation of Atlantic Tunas

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1967-1986, compiled from statistics about ICCAT fishery region L4

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

Spatially explicit estimates of stock size, structure and biomass of North Atlantic albacore tuna (Thunnus alalunga) in the North Atlantic for the period 1956-1972, compiled from statistics about ICCAT fishery region L1

The development of the ecosystem approach and models for the management of ocean marine resources requires easy access to standard validated datasets of historical catch data for the main exploited species. They are used to measure the impact of biomass removal by fisheries and to evaluate the models skills, while the use of standard dataset facilitates models inter-comparison. North Atlantic albacore tuna is exploited all year round by longline and in summer and autumn by surface fisheries and fishery statistics compiled by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Catch and effort with geographical coordinates at monthly spatial resolution of 1° or 5° squares were extracted for this species with a careful definition of fisheries and data screening. In total, thirteen fisheries were defined for the period 1956-2010, with fishing gears longline, troll, mid-water trawl and bait fishing. However, the spatialized catch effort data available in ICCAT database represent a fraction of the entire total catch. Length frequencies of catch were also extracted according to the definition of fisheries above for the period 1956-2010 with a quarterly temporal resolution and spatial resolutions varying from 1°x 1° to 10°x 20°. The resolution used to measure the fish also varies with size-bins of 1, 2 or 5 cm (Fork Length). The screening of data allowed detecting inconsistencies with a relatively large number of samples larger than 150 cm while all studies on the growth of albacore suggest that fish rarely grow up over 130 cm. Therefore, a threshold value of 130 cm has been arbitrarily fixed and all length frequency data above this value removed from the original data set.

FP7-PEOPLE, Marine protected areas for the conservation of marine top predators (MPACONTOP)

The state of the global oceans is rapidly deteriorating due to the effect of human activities, and the risk of extinction to marine species is far greater than previously thought. The main threat to the marine environment is posed by over-fishing, which has resulted, in many cases, in extinctions of both target and incidentally caught species, including marine top predators (e.g. large pelagic fish, turtles, cetaceans, and seabirds). Seabirds belonging to the order Procellariiformes are amongst the most pelagic of seabirds and occur in all of the world's oceans. Although Procellariiformes face many threats at their breeding habitat, fishing activity is their main conservation problem since many thousands of birds are killed annually by longline fisheries and populations have shown marked declines over the last decades, especially in the Southern Ocean. The proposed research will develop effective conservation strategies for marine top predators, taking into account their spatiotemporal population dynamics as well as the dynamics of longline fisheries. Our modeling approach will be based on data from the Tracking Ocean Wanderers conservation initiative, which covers over 90Prozent of all extant Procellariiformes tracking data. The complexity of these challenges requires a multidisciplinary approach which integrates the most recent techniques of GIS-based habitat modeling, individual-based and spatially-explicit, pattern-oriented, population viability analyses and multi-criteria decision analysis, which will be develop in a world leading center of ecological modeling, the Helmholtz Centre for Environmental Research UFZ. This combined approach will facilitate the identification of suitable habitat for the implementation of marine protected areas for the conservation of marine top predators in the Southern Ocean, as well as simulations performance in order to assess the effectiveness of different fishery management scenarios, which is impossible at sea.

Galeorhinus galeus (Linnaeus, 1758) Hundshai Meeresfische und -neunaugen Vom Aussterben bedroht

Für die Verantwortlichkeitsanalyse in Bezug auf den Hundshai wurde berücksichtigt, dass die Art durch die IUCN aktuell weltweit als vom Aussterben bedroht (Critically Endangered) eingestuft wird (IUCN 2023). Der Hundshai ist weltweit in den borealen und gemäßigten Zonen der Nord- und Südhalbkugel verbreitet. Sein Verbreitungsgebiet im Ostatlantik reicht von Island und Nordnorwegen bis Südafrika, auch im Mittelmeer kommt die Art vor (Zidowitz et al. 2017). Insofern liegen die deutschen Meeresgebiete mit im Hauptareal der Art. Der Bestandsanteil des Hundshais beträgt hier weniger als 10% seines Weltbestandes. Insgesamt ist Deutschland für die weltweite Erhaltung der Art in besonders hohem Maße verantwortlich. Beim Hundshai (Abb.: siehe Publikation für Abbildungsnummer) änderte sich aufgrund von Kenntniszuwachs durch die Berücksichtigung der Analysen zur historischen Bestandsentwicklung der Art seit 1902 in den neueren Arbeiten von Fock et al. (2014) und Sguotti et al. (2016) die Einschätzung des langfristigen Bestandstrends von der Kriterienklasse „starker Rückgang“ auf „Rückgang unbekannten Ausmaßes“. Reale Veränderungen in Form von stark abnehmenden Präsenzen der Art in der deutschen Nordsee im Zeitraum von 2002 bis 2021 waren der Grund für die geänderte Einschätzung des kurzfristigen Bestandstrends von der Kriterienklasse „Abnahme unbekannten Ausmaßes“ hin zu „starke Abnahme“. Zusätzlich liegt ein Risikofaktor vor. Dies führte insgesamt zur Einstufung der Art in der vorliegenden Roten Liste in die RL-Kategorie „Vom Aussterben bedroht“, während die Art in der vorherigen Roten Liste noch als stark gefährdet eingestuft worden war. NORDSEE: Ein Hauptgrund für die Gefährdung des Hundshais ist sein Beifang in der Schleppnetz- und Langleinenfischerei (vgl. Kap. (siehe Publikation für Kapitelnummer), Gefährdungsursache: Fischerei indirekt). Weiterhin ist er eine wichtige Zielart in der hobbymäßigen Angelfischerei (ICES 2019, Zidowitz et al. 2017). Zukünftige Risiken für die Art bestehen im geplanten massiven Ausbau der Offshore-Windparks (BMWK 2023) in Verbindung mit der Verlegung von Seekabeln und der vorgesehenen Schlickverklappung südlich von Helgoland. OSTSEE: Durch die HELCOM (2013) wird die Art für die gesamte Ostsee als gefährdet (Vulnerable) eingestuft. NORDSEE: Genetische Untersuchungen und Markierungsdaten haben gezeigt, dass es mindestens fünf getrennte Teilpopulationen des Hundshais gibt, ohne dass bisher Belege für eine Vermischung zwischen ihnen existieren. Hundshaie sind generell sehr wanderungsfreudig. Auch in europäischen Gewässern führen sie Wanderungen über große Distanzen durch, so z.B. von der Deutschen Bucht durch den Ärmelkanal bis in den Nordostatlantik.

Raja clavata Linnaeus, 1758 Nagelrochen Meeresfische und -neunaugen Vorwarnliste

Beim Nagelrochen ergab sich eine mehrstufige Verbesserung der RL-Kategorie „Vom Aussterben bedroht“ der vorherigen Roten Liste. Die Art steht in der vorliegenden Roten Liste auf der Vorwarnliste. Hierzu führten Änderungen in der Einschätzung der aktuellen Bestandssituation, des langfristigen und kurzfristigen Bestandstrends sowie des Risikos. Die Präsenz-Zeitserie zeigt für die Art in der deutschen Nordsee eine deutliche Zunahme seit 2012, so dass der kurzfristige Bestandstrend aufgrund dieser realen Veränderung von der Kriterienklasse „starke Abnahme“ zu „deutliche Zunahme“ geändert wurde sowie die aktuelle Bestandssituation von der Kriterienklasse „extrem selten“ auf „selten“ angehoben wurde. Die Änderungen im kurzfristigen Bestandstrend führten in Verbindung mit der Auswertung neuer Analysen von Surveydaten zum Nagelrochen seit 1902 von Fock (2014), Fock et al. (2014)Fock et al. (2014) und Sguotti et al. (2016) aufgrund von Kenntniszuwachs auch zur Neubewertung des langfristigen Bestandstrends der Art, dessen Einschätzung von der Kriterienklasse „sehr starker Rückgang“ zu „starker Rückgang“ geändert wurde. Außerdem entfielen die beim Kriterium „Risiko/stabile Teilbestände“ herausgestellten verstärkten direkten Einwirkungen. Der Nagelrochen wird auch weltweit auf der Vorwarnliste (Near Threatened) geführt (IUCN 2023). NORDSEE: Früher wurde der Nagelrochen als die häufigste und am weitesten verbreitete Rochenart in den deutschen Gebieten der Nordsee angesehen, der dort auch bis in flache Wattenmeergebiete und in Flussmündungsgebiete hinein vorkam (Bloch 1785, Wittmack 1875, Heincke 1894, Duncker et al. 1929, Ehrenbaum 1936, Zidowitz et al. 2017). Langfristig ging der Bestand der Art stark zurück. Zu den wichtigsten Gefährdungsursachen der Art zählen direkte und indirekte Auswirkungen der Fischerei. Nach Zidowitz et al. (2017) gehören dazu vor allem Kiemennetz- und Langleinenfischerei sowie die Beifänge der Schleppnetzfischerei. Weiterhin werden von Zidowitz et al. (2017) u.a. Eutrophierung, anthropogene Lärmemissionen und Habitatverluste als Gefährdungsursachen des Nagelrochens genannt. Zwar liegt aktuell kein Status Assessment der OSPAR-Kommission für den Nagelrochen vor, jedoch wird die Art in der Liste der gefährdeten Arten geführt (OSPAR 2023). OSTSEE: Durch die HELCOM (2013) wird der Nagelrochen für die gesamte Ostsee als gefährdet (Vulnerable) eingestuft. Er kommt nur im Skagerrak bis Kattegat vor, in der deutschen Ostsee ist er eine unbeständige Art. NORDSEE: Nach Einschätzung des ICES (ICES Advice 2022) zeigt die Population in der Nordsee seit 2005 eine deutliche Erholung. In den letzten Jahren wurden auch in den deutschen Nordseeästuaren wieder Nagelrochen in geschleppten Fanggeräten als Beifang registriert.

Alopias vulpinus (Bonnaterre, 1788) Fuchshai Meeresfische und -neunaugen Extrem selten

Spezifisch für die deutschen Meeresgebiete gibt es keine Angaben zu den Gefährdungsursachen des Fuchshais. Weltweit wird die Art als gefährdet (Vulnerable) eingestuft (IUCN 2023). Für den europäischen Raum werden seitens IUCN (2023) für den Fuchshai indirekte Auswirkungen der Fischerei in Form von Beifang als eine Gefährdungsursache genannt, v.a. in der Langleinenfischerei auf Thunfisch und Schwertfisch, aber auch in der Treibnetz- und Kiemennetzfischerei. Wie Knorpelfische insgesamt sind Fuchshaie aufgrund ihres Lebenszyklus (späte Geschlechtsreife, wenige Nachkommen) sehr anfällig für eine übermäßige Nutzung der Bestände. Da Fleisch und Flossen der Fuchshaie einen hohen Handelswert haben, ist der weitgehend unregulierte Handel mit Haifischflossen weltweit als ernsthafte Bedrohung für Fuchshaie anzusehen. Außerdem werden Fuchshaie auch durch Öl- und Gasbohrungen sowie durch die Einrichtung von Schifffahrtswegen beeinträchtigt.

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