Age validation of the North Atlantic stock of wreckfish (Polyprion americanus), based on bomb radiocarbon (14C), and new estimates of life history parameters

Albacore (Thunnus alalunga) in the North Atlantic Ocean is currently managed as a single well-mixed stock, although this assumption remains contentious. We measured stable isotopes (δ13C and δ18O) and trace elements (Mg, Mn, Sr, Ba) in otoliths of albacore collected from two feeding grounds, namely the Bay of Biscay and Atlantic offshore waters, and compared them among sampling locations and life history stages. Measurements in otolith core, post-core and edge were used to determine whether albacore from these two regions have the same nursery origin and migratory patterns. We found no clear evidence of distinct nursery grounds based on otolith core chemistry, but Sr:Ca and Mg:Ca were different in the post-core portions of albacore from the two locations, suggesting residency in different regions during the early juvenile stage. Otolith edge chemistry, particularly stable isotopes and Sr:Ca, proved to be a valuable tool for classifying individuals to their capture locations. Annual cycles of Sr:Ca ratios were visible along life history transects, likely reflecting migratory patterns between water masses of differing salinity, but the timing of Sr:Ca cycles differed between the two groups. Differentiation in trace element concentrations in the otolith post-core and the timing of Sr:Ca cycles suggest the occurrence of two migratory contingents of albacore in the north-east Atlantic Ocean.

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Environmental change influences the life history of salmon Salmo salar in the North Atlantic Ocean

Journal of Fish Biology ◽

10.1111/jfb.12854 ◽

2016 ◽

Vol 88 (2) ◽

pp. 618-637 ◽

Cited By ~ 29

Author(s):

B. Jonsson ◽

N. Jonsson ◽

J. Albretsen

Keyword(s):

Life History ◽

Atlantic Ocean ◽

Environmental Change ◽

Salmo Salar ◽

North Atlantic ◽

North Atlantic Ocean ◽

The North ◽

History Of ◽

The North Atlantic

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Calicobenedenia polyprioni n. gen., n. sp. (Monogenoidea: Capsalidae) from the External Surfaces of Wreckfish, Polyprion americanus (Teleostei: Polyprionidae), in the North Atlantic

Journal of Parasitology ◽

10.2307/3285618 ◽

1999 ◽

Vol 85 (2) ◽

pp. 192 ◽

Cited By ~ 8

Author(s):

Delane C. Kritsky ◽

Colleen J. Fennessy

Keyword(s):

North Atlantic ◽

The North ◽

The North Atlantic ◽

Polyprion Americanus

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Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals

Life in the Slow Lane: Ecology and Conservation of Long-Lived Marine Animals ◽

10.47886/9781888569155.ch4 ◽

1999 ◽

Keyword(s):

Life History ◽

Northern Hemisphere ◽

North Atlantic ◽

The United States ◽

Individual Transferable Quota ◽

The North ◽

Mainland Portugal ◽

Management Plans ◽

The North Atlantic ◽

The Mediterranean

<em>Abstract.</em> —The wreckfish <em>Polyprion americanus </em> is a long-lived, globally distributed species that supports fisheries on both sides of the Atlantic Ocean, in the Mediterranean, and in the western South Pacific. Wreckfish in the western North Atlantic have a life history that includes an extended (perhaps for two years) pelagic juvenile stage that drifts in the North Atlantic gyre; slow growth rates after assuming demersal existence; recruitment to the American fishery resulting from migration to the grounds at an advanced age (four years); and a long life (31 years at 1460 mm total length and 47 kg total weight). Experience with wreckfish in isolated geographic habitats such as Bermuda indicates that wreckfish can be quickly overfished as fishing technology develops to target the species. Because of its life history and evidence for a single stock of wreckfish for the northern hemisphere, recruitment to local fisheries may depend on management imposed by agencies that regulate distant fisheries. In the United States, the fishery is managed with an individual transferable quota (ITQ), which has sustained a small fishery (annual total allowable catch [TAC] = 907 metric tons) similar in magnitude to that in the Azores and mainland Portugal. There is no management in other portions of the northern hemisphere range. With the exception of Bermuda and perhaps the Mediterranean, northern hemisphere wreckfish stocks do not appear to be in decline; however, landings in the Azores and Madeira have decreased since 1994, after initial increases resulting from introduction of longlines. Current exploratory fishing on the Mid-Atlantic Ridge and probable expansion of landings of deepwater species in the North Atlantic islands may result in expansion of the fishery and may necessitate international management plans.

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