Grenadiers of the World Oceans: Biology, Stock Assessment, and Fisheries

<em>Abstract</em>.—The biology and fisheries of macrourid species in the NE Atlantic are reviewed. Of about 30 species that occur within that area, the roundnose grenadier <em>Coryphaenoides rupestris </em>is one of the main target species of deep-water fisheries. Roughhead grenadier <em>Macrourus berglax </em>is a minor bycatch of other deep-water fisheries and an occasional target of some small fisheries. Other macrourid species are not commercially exploited because they are too small and/or in too deep waters, but some are also taken as accidental bycatch. There are three main fisheries for roundnose grenadier: north and west of the British Isles, Skagerrak, and Mid-Atlantic Ridge. The Skagerrak fishery is mainly for fish meal while the others are for human consumption. Due to data availability, a range of assessment methods has been trialled primarily for stocks to the north and west of the British Isles. Although uncertain, these assessments provide evidence that the stock has been severely depleted. Fisheries were largely unregulated until the early 2000s, but following repeated International Council for the Exploration of the Sea (ICES) advice, total allowable catches were introduced in 2003 together with effort and capacity regulations. Roundnose grenadier is the most studied species. It lives more than 50 years, compared to 30 years or more for roughhead grenadier. The limited knowledge of other species suggests a contrasting picture of maximum age ranging from 10 to 40 years. Taking into account the limited biological knowledge for these species, the pros and cons of the current management regime are discussed.

<em>Abstract</em>.—Total body length of roundnose grenadier <em>Coryphaenoides rupestris </em>reaches 123 cm at maximum observed age of 30 years. In the Northwest Atlantic, predominating length is 50–70 cm, in the area of Mid-Atlantic Ridge and off Europe, 50–90 cm. Average length at maturity is 76 cm. Main spawning takes place in the Northeast Atlantic in summer-autumn. Mean fecundity is 30,000 eggs. Grenadier occur mainly near the bottom, but somtimes in the pelagic layer. Vertical migrations are very variable. Long distance horizontal migrations of adults have not been recorded. There is no consensus about population structure. In the Northwest Atlantic the greatest catch (83,700 t) was taken in 1971. Since then the fishery declined until it was stopped completely. On the Mid-Atlantic Ridge, the maximum catch (29,900 t) was taken in 1973, after which catches decreased. In the last 15 years, in the European waters, catches increased and reached 28,900 t in 2004. In the majority of the areas the stock size is at the low level. In the Northeast Atlantic (including the Mid-Atlantic Ridge) the fishery is regulated by NEAFC by the restriction of fishing effort and closed areas. In the Northwest Atlantic, directed fishery is banned by NAFO. In the North Atlantic, in the whole fishing period, the international catch amounted to about 1,000,000 t.


2009 ◽  
Vol 49 (1) ◽  
pp. 465
Author(s):  
Thomas Bernecker

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. This year, 31 areas plus two special areas in five offshore basins are being released for work program bidding. Closing dates for bid submissions are either six or twelve months after the release date (i.e. 3 December 2009 and 29 April 2010), depending on the exploration status in these areas is and on data availability. The 2009 release areas are located in Commonwealth waters offshore Northern Territory, Western Australia, South Australia and Victoria, comprising intensively explored areas close to existing production as well as new frontiers. As usual, the North West Shelf features very prominently and is complimented by new areas along the southern margin, including frontier exploration areas in the Ceduna Sub-basin (Bight Basin) and the Otway Basin. The Bonaparte Basin is represented by one release area in the Malita Graben, while five areas are available in the Southern Browse Basin in an under-explored area of the basin. A total of 14 areas are being released in the Carnarvon Basin, with eight areas located in the Dampier Sub-basin, three small blocks in the Rankin Platform and three large blocks on the Northern Exmouth Plateau (these are considered a deep water frontier). In the south, six large areas are on offer in the Ceduna Sub-basin and five areas of varying sizes are being released in the Otway Basin, including a deep water frontier offshore Victoria. The special release areas are located in the Petrel Sub-basin, Bonaparte Basin offshore Northern Territory, and encompass the Turtle/Barnett oil discoveries. The 2009 offshore acreage release offers a wide variety of block sizes in shallow as well as deep water environments. Area selection has been undertaken in consultation with industry, the states and Territory. This year’s acreage release caters for the whole gamut of exploration companies given that many areas are close to existing infrastructure while others are located in frontier offshore regions. As part of Geoscience Australia’s Offshore Energy Security Program, new data has been acquired in offshore frontier regions and have yielded encouraging insights into the hydrocarbon prospectivity of the Ceduna-Sub-basin.


<em>Abstract.—</em>The Mid-Atlantic Ridge of the North Atlantic is inhabited by at least 16 macrourid species in 9 genera. The species composition and distribution patterns are analysed based on bottom trawl catches in the depth range 985 to 3461m conducted on the 2004 MAR-ECO expedition between the Azores and the southern Reykjanes Ridge. Some of the species, e.g. roundnose grenadier <em>Coryphaenoides rupestris</em>, <em>C. brevibarbis </em>and abyssal grenadier <em>C. armatus, </em>rank among the most abundant demersal fishes on the ridge or in the deep axial valleys or fracture zones, while others are uncommon or rare. While a few species have apparently restricted northerly or southerly distributions, most are widespread. Among common species that occur along the entire ridge section investigated, there are indications of structuring by depth of occurrence.


Zootaxa ◽  
2011 ◽  
Vol 2869 (1) ◽  
pp. 54 ◽  
Author(s):  
TAMMY HORTON ◽  
MICHAEL THURSTON

A new species of Centromedon Sars, 1891 is described based on abundant material collected in baited traps at 2500 m on the Mid-Atlantic Ridge. The species can be distinguished from the most closely allied species, Centromedon typhlops (Sars, 1879), Centromedon mediator (Barnard, 1962) comb. nov. and Centromedon laevis (Bonnier, 1896) comb. nov., by the form of the gnathopods, and characters of the mouthparts. A key to the eight species in the genus is provided. The differences between the closely allied genera Uristes Dana, 1849 and Centromedon are discussed.


Author(s):  
Eve C. Southward

In May 1958 it was thought that all species of Pogonophora so far discovered in the north-east Atlantic belonged to the genusSiboglinumCaullery (Southward & Southward, 1958). Since then I have had the opportunity of examining further collections from deep water off the British Isles and Spain. At least two species of multitentaculate pogonophores have been discovered, and re-examination of some material collected in May 1958 shows that one of the species was also present in these collections. Although considerable material belonging to other species remains to be worked up it has been thought worth while to describe these two species first. One is widespread and can be locally abundant, while the other is the largest pogonophote so far found in the Atlantic. Both are the first Atlantic representatives of their respective genera.


Author(s):  
Jan H. Stock

Ten species of deep-water Pycnogonida are recorded, mainly from the north-eastern Atlantic Basin. Of particular interest are Ascorhynchus abyssi Sars (new to the British Isles), Colossendeis arcuata A. Milne Edwards (northernmost record in European waters), C. bicinc0ta Schimkewitsch (third Atlantic record, depth range increased), C. macerrima Wilson (new records from the English Channel), Nymphon laterospinum Stock (new to the Indian Ocean), Pallenopsis (Bathypallenopsis) oscitans (Hoek) (new to the English Channel and bathymetrical range extension), P. (B.) tritonis Hoek (extension of depth range), P. (B.) tydemani caraibica Stock (second European record, now found at the entrance of the English Channel), and Anoplodactylus arnaudae Stock (range extended to the Rockall Trench).


1992 ◽  
Vol 13 (1) ◽  
pp. 141-147 ◽  
Author(s):  
J. W. Murray

AbstractMost of the British Isles has been a land area throughout the Tertiary and the basic shape of the coastline had been determined by the late Palaeocene. Only in southeast England are there marine Palaeogene and Neogene successions and these were deposited in embayments marginal to the North Sea and English Channel.Much of the key information for the interpretation of the Tertiary history of the British Isles lies offshore. Thousands of kilometres of seismic profiles have been run and hundreds of boreholes drilled, mainly in the search for oil. The only part of the Tertiary which has been of economic interest is the Palaeocene of the northern North Sea. Summaries of the offshore data are given in Woodland (1975) and Illing & Hobson (1981).Thick Tertiary successions are known from the central Graben of the North Sea, the Rockall Trough and the Faeroe Basin (Map Pg 1). The North Sea was the site of great subsidence caused by thermal relaxation following stretching of the continental crust (Sclater & Christie 1980). None of the Tertiary sediments was deposited in very deep water. By contrast, the Rockall Trough and the Faeroe Basin are underlain by oceanic crust and deep water has existed there throughout the Tertiary. The successions are known only from seismic studies (Roberts 1975) but are thought to be mainly fine-grained and with some contourites.On a regional scale, the Tertiary history of northwest Europe must be considered in relation to the plate tectonic events proceeding in the adjacent ocean.


2009 ◽  
Vol 66 (2) ◽  
pp. 323-333 ◽  
Author(s):  
Philip A. Large ◽  
Norman G. Graham ◽  
Nils-Roar Hareide ◽  
Robert Misund ◽  
Dominic J. Rihan ◽  
...  

Abstract Large, P. A., Graham, N. G., Hareide, N-R., Misund, R., Rihan, D. J., Mulligan, M. C., Randall, P. J., Peach, D. J., McMullen, P. H., and Harlay, X. 2009. Lost and abandoned nets in deep-water gillnet fisheries in the Northeast Atlantic: retrieval exercises and outcomes. – ICES Journal of Marine Science, 66: 323–333. The methods used and the results, including estimates of ghost catches present at the time of retrieval, from Irish and UK (England and Wales) gillnet retrieval exercises carried out in deep-water gillnet fisheries west of the British Isles are described. Summaries of the exercises are currently found only in the grey literature, and there is a need to make them more widely available to the scientific community. The fisheries are currently principally for anglerfish (mainly Lophius piscatorius), along with a small bycatch of deep-water sharks [mainly leafscale gulper shark (Centrophorous squamosus) and Portuguese dogfish (Centroscymnus coelolepis)]. The methods used and the results from retrieval exercises in the Norwegian Greenland halibut (Reinhardtius hippoglossus) gillnet fishery are also presented. It is suggested that the efficiency of the Norwegian retrieval gear (which was used in all but one of the retrieval exercises described) be investigated under a range of conditions using an attached underwater camera. The outcomes from this could be used to improve the design of retrieval gear and future gillnet retrieval survey/mitigation exercises. Suggestions are made to improve the format and interpretation of results from future retrieval surveys and to enhance their value to fishery managers and stock assessment scientists. The importance of the continued need for structured gillnet retrieval exercises in deep-water gillnet fisheries is emphasized, and suggestions are made for conducting future studies.


1998 ◽  
Vol 180 ◽  
pp. 163-167
Author(s):  
Antoon Kuijpers ◽  
Jørn Bo Jensen ◽  
Simon R . Troelstra ◽  
And shipboard scientific party of RV Professor Logachev and RV Dana

Direct interaction between the atmosphere and the deep ocean basins takes place today only in the Southern Ocean near the Antarctic continent and in the northern extremity of the North Atlantic Ocean, notably in the Norwegian–Greenland Sea and Labrador Sea. Cooling and evaporation cause surface waters in the latter region to become dense and sink. At depth, further mixing occurs with Arctic water masses from adjacent polar shelves. Export of these water masses from the Norwegian–Greenland Sea (Norwegian Sea Overflow Water) to the North Atlantic basin occurs via two major gateways, the Denmark Strait system and the Faeroe– Shetland Channel and Faeroe Bank Channel system (e.g. Dickson et al. 1990; Fig.1). Deep convection in the Labrador Sea produces intermediate waters (Labrador Sea Water), which spreads across the North Atlantic. Deep waters thus formed in the North Atlantic (North Atlantic Deep Water) constitute an essential component of a global ‘conveyor’ belt extending from the North Atlantic via the Southern and Indian Oceans to the Pacific. Water masses return as a (warm) surface water flow. In the North Atlantic this is the Gulf Stream and the relatively warm and saline North Atlantic Current. Numerous palaeo-oceanographic studies have indicated that climatic changes in the North Atlantic region are closely related to changes in surface circulation and in the production of North Atlantic Deep Water. Abrupt shut-down of the ocean-overturning and subsequently of the conveyor belt is believed to represent a potential explanation for rapid climate deterioration at high latitudes, such as those that caused the Quaternary ice ages. Here it should be noted, that significant changes in deep convection in Greenland waters have also recently occurred. While in the Greenland Sea deep water formation over the last decade has drastically decreased, a strong increase of deep convection has simultaneously been observed in the Labrador Sea (Sy et al. 1997).


1992 ◽  
Vol 26 (12) ◽  
pp. 2705-2709 ◽  
Author(s):  
H. M. Austin

The Chesapeake Bay, while a significant habitat for fisheries resources, is in actuality an aquatic “bedroom community”, as many of the economically important species are seasonally transient. The pressure on these resources due to their demand for human consumption and recreation, proximity to extensive industrial activity along the shores, and climate scale environmental fluctuations has resulted in stock declines by most important species. Our inability to separate natural population fluctuations from those of anthropogenic origin complicates management efforts. The only way to make these separations, and subsequent informed management decisions is by supporting long-term stock assessment programs (monitoring) in the Bay which allow us to examine trends, cycles and stochastic processes between resource and environment. These programs need to monitor both recruitment and fishing mortality rates of the economically important species, and to identify and monitor the environmentally sensitive “canary” species.


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