scholarly journals Contributions to Management Strategies in the NE Atlantic Regarding the Life History and Population Structure of a Key Deep-Sea Fish (Mora moro)

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 522
Author(s):  
Régis Santos ◽  
Wendell Medeiros-Leal ◽  
Osman Crespo ◽  
Ana Novoa-Pabon ◽  
Mário Pinho
Keyword(s):  
Population Structure ◽  
Life History ◽  
Deep Sea ◽  
Management Strategies ◽  
Size Composition ◽  
Large Size ◽  
The Common ◽  
Fishing Impacts ◽  
Sea Fish

With the commercial fishery expansion to deeper waters, some vulnerable deep-sea species have been increasingly captured. To reduce the fishing impacts on these species, exploitation and management must be based on detailed and precise information about their biology. The common mora Mora moro has become the main deep-sea species caught by longliners in the Northeast Atlantic at depths between 600 and 1200 m. In the Azores, landings have more than doubled from the early 2000s to recent years. Despite its growing importance, its life history and population structure are poorly understood, and the current stock status has not been assessed. To better determine its distribution, biology, and long-term changes in abundance and size composition, this study analyzed a fishery-dependent and survey time series from the Azores. M. moro was found on mud and rock bottoms at depths below 300 m. A larger–deeper trend was observed, and females were larger and more abundant than males. The reproductive season took place from August to February. Abundance indices and mean sizes in the catch were marked by changes in fishing fleet operational behavior. M. moro is considered vulnerable to overfishing because it exhibits a long life span, a large size, slow growth, and a low natural mortality.

scholarly journals RETRACTED ARTICLE: Novel life history strategy in a deep sea fish challenges assumptions about reproduction in extreme environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Randal A. Singer ◽  
Jon A. Moore ◽  
Edward L. Stanley
Keyword(s):  
Life History ◽  
Deep Sea ◽  
Extreme Environments ◽  
Life History Strategy ◽  
Deep Ocean ◽  
Homogeneous System ◽  
Life History Strategies ◽  
Life History Trait ◽  
Retracted Article ◽  
Sea Fish

Abstract The deep ocean is frequently assumed to be a homogeneous system lacking the same diverse life history strategies found in shallower waters. However, as our methods for exploring the deep ocean improve, common assumptions about dispersal, reproduction and behavior are constantly being challenged. Fishes exhibit the most diverse reproductive strategies among vertebrates. Understanding life history strategies in deep-sea environments is lacking for many species of fishes. Here, we report a novel reproductive strategy where a fish (Parazen pacificus) provides parental care via mouth brooding. This behavior is observed from a specimen collected with eggs present in the buccal cavity, along with other specimens exhibiting pre-brooding morphologies. This is the first description of this unique life history trait in a deep-sea fish and fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.

Kokanee–sockeye salmon hybridization leads to intermediate morphology and resident life history: implications for fisheries management

2020 ◽  
Vol 77 (2) ◽  
pp. 355-364
Author(s):  
Lucas D. Elliott ◽  
Hillary G.M. Ward ◽  
Michael A. Russello
Keyword(s):  
Life History ◽  
Sockeye Salmon ◽  
Management Strategies ◽  
Empirical Support ◽  
Intermediate Morphology ◽  
Intermediate Size ◽  
Freshwater Resident ◽  
Historical Range ◽  
Hybridization And Introgression

Stocking programs designed to return extirpated species to their historical range have become increasingly prevalent, punctuating the need to better understand the risks posed to recipient ecosystems. Here, we investigated the genetic and biological consequences of an anadromous sockeye salmon (Oncorhynchus nerka) stocking program in Skaha Lake, British Columbia, where substantial levels of hybridization and introgression with the native freshwater resident ecotype (kokanee) have been detected. We genetically assigned 543 individuals (adult spawners, age-0 juveniles) to estimate stock proportions (pure-stock sockeye, pure-stock kokanee, or hybrid) between 2010 and 2017, with a subset undergoing otolith microchemistry analysis to determine migratory life history and maternal ancestry. The proportion of hybrid spawners varied from 5% to 20% across sampling years, while that of hybrid age-0 juveniles remained relatively constant (∼11%). Hybrid spawners exhibited intermediate size relative to pure stocks, with the vast majority being nonanadromous (92%) and of resident maternal ancestry (76%). Our results provide empirical support for previously hypothesized mechanisms of hybridization between O. nerka life-history forms and underscore the importance of continued monitoring of stocking programs to quantify long-term fitness impacts of introgression and refine management strategies.

scholarly journals Extent of Variation of the Bacillus thuringiensis Toxin Reservoir: the Case of the Geranium Bronze, Cacyreus marshalli Butler (Lepidoptera: Lycaenidae)

2002 ◽  
Vol 68 (8) ◽  
pp. 4090-4094 ◽  
Author(s):  
Salvador Herrero ◽  
Marisé Borja ◽  
Juan Ferré
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Management Strategies ◽  
Resistance Management ◽  
Cross Resistance ◽  
Binding Studies ◽  
Cry Proteins ◽  
Combined Use ◽  
The Common

ABSTRACT Despite the fact that around 200 cry genes from Bacillus thuringiensis have already been cloned, only a few Cry proteins are toxic towards a given pest. A crucial step in the mode of action of Cry proteins is binding to specific sites in the midgut of susceptible insects. Binding studies in insects that have developed cross-resistance discourage the combined use of Cry proteins sharing the same binding site. If resistance management strategies are to be implemented, the arsenal of Cry proteins suitable to control a given pest may be not so vast as it might seem at first. The present study evaluates the potential of B. thuringiensis for the control of a new pest, the geranium bronze (Cacyreus marshalli Butler), a butterfly that is threatening the popularity of geraniums in Spain. Eleven of the most common Cry proteins from the three lepidopteran-active Cry families (Cry1, Cry2, and Cry9) were tested against the geranium bronze for their toxicity and binding site relationships. Using 125I-labeled Cry1A proteins we found that, of the seven most active Cry proteins, six competed for binding to the same site. For the long-term control of the geranium bronze with B. thuringiensis-based insecticides it would be advisable to combine any of the Cry proteins sharing the binding site (preferably Cry1Ab, since it is the most toxic) with those not competing for the same site. Cry1Ba would be the best choice of these proteins, since it is significantly more toxic than the others not binding to the common site.

scholarly journals Retraction Note: Novel life history strategy in a deep sea fish challenges assumptions about reproduction in extreme environments

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Randal A. Singer ◽  
Jon A. Moore ◽  
Edward L. Stanley
Keyword(s):  
Life History ◽  
Deep Sea ◽  
Extreme Environments ◽  
Life History Strategy ◽  
Link Type ◽  
Sea Fish

Editor's Note: this Article has been retracted; the Retraction Note is available at https://doi.org/10.1038/s41598-020-75408-8

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

2008 ◽  
Keyword(s):  
New Species ◽  
Deep Sea ◽  
Stock Assessment ◽  
Southwestern Atlantic ◽  
The World ◽  
Fish Group ◽  
Sea Fish ◽  
The U.S

<em>Abstract.</em>—Grenadiers have been known since 1765, but it was not until the <em>Challenger </em>expedition that grenadiers were recognized as a major deep sea fish group. Known species of grenadiers increased dramatically between 1870 and 1900, peaking at the end of that century, and rising again between 1900 and 1920 from collections of the <em>Albatross</em>. After 1920, grenadier taxonomy languished until the1970s, peaking in the 1990s when 74 new species were described. There are now approximately 394 valid grenadier species with many yet to be described. The classification of gadiform fishes has been much debated, but placement of grenadiers within the order Gadiformes is relatively firmly established. Opinions still differ, however, on relationships of the four major grenadier groups, with bathygadids the most contentious group. Long-term fisheries for grenadiers began in the late 1960s, targeting primarily the roundnose grenadier. After a peak catch of about 84,000 tons in 1971, catches of that species have diminished. Exploitation of the roughhead grenadier <em>Macrourus berglax </em>began in the 1980s. Minor fisheries currently exist for Pacific grenadier <em>Coryphaenoides acrolepis </em>off the U.S. West Coast and for two <em>Macrourus </em>species in the southwestern Atlantic.

Distribution and life history of deep-water squid of commercial interest from Australia

1985 ◽  
Vol 36 (3) ◽  
pp. 343 ◽  
Author(s):  
M Dunning ◽  
SB Brandt
Keyword(s):  
Life History ◽  
Southern Ocean ◽  
Continental Slope ◽  
Deep Water ◽  
Management Strategies ◽  
Common Species ◽  
Commercial Use ◽  
History Of ◽  
The Common ◽  
Mesopelagic Species

Squid of continental slope and oceanic waters are not currently fished commercially within the Australian Fishing Zone although one species has been caught occasionally in commercial quantities. At least eight species of the cosmopolitan family Ommastrephidae and a variety of mostly mesopelagic species of the families Enoploteuthidae and Onychoteuthidae are represented in Australian waters. The large ommastrephid species Ommastrephes bartrami (red ocean squid), Todarodes filippovae (Southern Ocean arrow squid) and Sthenofeuthis oualaniensis (yellowback squid) have the greatest potential for commercial use. Data on the life history and distribution of the common species are synthesized to provide a baseline for future scientific studies and management strategies.

Exploitation of deep-sea fishery resources

2020 ◽  
pp. 71-90
Author(s):  
Les Watling ◽  
Lissette Victorero ◽  
Jeffrey Drazen ◽  
Matthew Gianni
Keyword(s):  
Life History ◽  
Fisheries Management ◽  
Deep Sea ◽  
Environmental Harm ◽  
Fishing Gear ◽  
Bottom Trawling ◽  
Fish Stocks ◽  
Sea Bottom ◽  
Fish Catch ◽  
Sea Fish

Deep-sea fisheries occur at depths between 200 and 1800 m, using bottom trawls, long lines, and occasionally pots and gillnets. These fisheries were of minor interest and value until the mid-1980s when large stocks of fish were discovered, mostly on high-seas seamounts. However, because of the life-history characteristics of deep-dwelling fish, most seamount fish stocks were soon overfished, and few have recovered. Total deep-sea fish catch since 1950 represents about 3 per cent of the global catch, yet the environmental harm caused to deep-sea bottom communities by bottom trawling is extensive and long lasting, far exceeding the value of the fishery. In response, the United Nations has passed several resolutions since 2004 requiring the establishment of regional fisheries management organisations (RFMOs) who would be responsible for setting catch limits for the target species and requiring actions that would limit the damage to the habitat by fishing gear. To date, the latter of these two requirements, at least, has not been successfully met.

Long-term changes in the diversity, abundance and size composition of deep sea demersal teleosts from the Azores assessed through surveys and commercial landings

2019 ◽  
Vol 32 ◽  
pp. 25 ◽  
Author(s):  
Régis V.S. Santos ◽  
Wendell M.M.L. Silva ◽  
Ana M. Novoa-Pabon ◽  
Hélder M. Silva ◽  
Mario R. Pinho
Keyword(s):  
Deep Sea ◽  
Linear Models ◽  
Fork Length ◽  
Size Composition ◽  
Demersal Fish ◽  
Scientific Data ◽  
Marine Habitat ◽  
Important Species ◽  
Commercially Important

To obtain important baseline information about population dynamics and to provide valuable insights about the possible effects of artisanal fishing on the demersal fish community, this study had three specific objectives: (1) to update the annotated list of demersal teleost species occurring in the Azores (mid-North Atlantic); (2) to describe their depth distribution and related fishery information; and (3) to evaluate annual changes in their observed abundance and length composition. To do this, a time series with about 25 years of scientific data from the commercial fishery and surveys was analyzed. The demersal teleost community was represented by 213 species, predominantly deep-water species, reflecting the main marine habitat in the Azores region. Fishery takes place mainly in the intermediate strata (200–600 m), where the most commercially important species occur. No changing in the fork length (LF) distribution toward small individuals caused by size-selective fishing was detected in this study. The high variability observed in the LF data indicates the need for more accurate studies considering alternative statistical analyses (e.g., generalised linear models) to examine the possible factors (e.g. depth coverage, gear configuration, soak time, and fishing area) that cause this variability. On the other hand, the abundance indices of some commercially important species appear to have declined (Phycis phycis, Pontinus kuhlii, Conger conger, Beryx splendens and B. decadactylus), while others appear to be more stable (Helicolenus dactylopterus) or even increasing (Mora moro). Although the available data are insufficient for a formal assessment on the status of exploited populations, the long-term analysis of commercial landings and survey data was used as a basis to assess deep sea demersal teleost fisheries of the Azores, under a precautionary approach.

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