scholarly journals Influence of Levantine Artificial Reefs on the fish assemblage of the surrounding seabed

2009 ◽  
Vol 10 (1) ◽  
pp. 35 ◽  
Author(s):  
D. EDELIST ◽  
E. SPANIER
Keyword(s):  
Fish Assemblage ◽  
Artificial Reef ◽  
Artificial Reefs ◽  
Hard Substrate ◽  
Steady Increase ◽  
Important Species ◽  
Main Species ◽  
Commercially Important ◽  
Lessepsian Migrants ◽  
Siganus Rivulatus

Four Artificial Reef (AR) units were deployed at a 20m depth on a flat hard substrate 3 km west of Haifa, Israel and then surveyed for fish for 12 months. AR units supported 20 times the biomass of control quadrates and their enrichment impact was still significant at a radius of 13m away from units. The 13m values were also significantly higher than those of quadrates adjacent to units, suggesting the existence of a halo of relative depletion within the outer enrichment halo. The main species contributing to this pattern was the migrant herbivore Siganus rivulatus. A decrease in grazing resources is thus suggested as an explanation for creation of this halo. The most consistent AR residents were also Lessepsian migrants - Sargocentron rubrum, nocturnal predators which displayed high microhabitat fidelity and a steady increase in density. The 6 species of migrants recorded accounted for 65.3% of the commercially exploitable biomass and 25.2% of the specimens in the AR site. Other constant AR residents were the groupers Epinephelus costae and Epinephelus marginatus, which are rare and commercially important species. Site protection from fishing and storms were found to be of utmost importance, and design and deployment considerations are discussed.

Distinguishing resident from transient species along marine artificial reefs

2010 ◽  
Vol 90 (7) ◽  
pp. 1297-1303
Author(s):  
Etienne Boisnier ◽  
Tatsuyuki Sagawa ◽  
Teruhisa Komatsu ◽  
Norimasa Takagi
Keyword(s):  
Time Series ◽  
Reef Fish ◽  
Fish Assemblage ◽  
Efficient Solution ◽  
Artificial Reef ◽  
Artificial Reefs ◽  
Transient Species ◽  
Resident Species ◽  
Reef Fish Assemblage ◽  
Long Time

Even if artificial reef studies heavily refer to the distinction between resident and transient species, there is still no widely-shared available method to distinguish objectively these two groups. Such an absence makes any comparison between studies difficult. This study aims to test whether the four objective distinction methods successfully applied to a 21-year-long time-series on fish assemblage in an English estuary may be as successful when applied to marine artificial reefs. For such a purpose, we tested each distinction tool separately with reference to four different artificial reef fish assemblage datasets. Three of them were drawn from the literature. Results indicate that none of these tools, used either individually or collectively, provide an efficient solution to distinguish resident species for the four datasets considered. We suggest that one of the major reasons for this failure may lie in the relative sampling size. Nonetheless, as these four datasets are representative of the datasets generally reported in the literature, tools capable of distinguishing reliably and efficiently resident from transient species along artificial reefs have yet to be developed. However, such a development requires fish residence to be previously and accurately defined by artificial reef scientists and managers.

scholarly journals Fish larvae off the northwestern coast of the Baja California Peninsula, Mexico

Check List ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 334 ◽  
Author(s):  
S. Patricia A. Jiménez-Rosenberg ◽  
Ricardo J. Saldierna-Martínez ◽  
Gerardo Aceves-Medina ◽  
Alejandro Hinojosa-Medina ◽  
René Funes-Rodríguez ◽  
...  
Keyword(s):  
Reproductive Behavior ◽  
Fish Assemblage ◽  
Community Dynamics ◽  
Baja California ◽  
Larval Fish ◽  
Fish Larvae ◽  
Distribution Patterns ◽  
Baja California Peninsula ◽  
Important Species ◽  
Commercially Important

The structure of the larval fish assemblage of the northwestern Pacific coast of Mexico is analyzed from zooplankton samples taken between 1998 and 2000 off northern and southern Baja California Peninsula. The 198 fish taxa identified reflected the faunal complexity reported previously for the area. Adult distribution patterns and reproductive behavior, added to the environmental seasonality and bathymetric characteristics of the coast, explained differences in the larval fish assemblage. Larvae of meso- and bathypelagics Vinciguerria lucetia, Diogenichthys laternatus, and Triphoturus mexicanus were the most abundant year round. Larvae of commercially important species, such as Engraulis mordax, Sardinops sagax, Merluccius productus, and Trachurus symmetricus, were also abundant during winter and spring, depending on the year and surveyed region. Adult distribution patterns and reproductive behavior, intra- and interannual environmental variability, and bathymetric characteristics of the coast all likely contributed to the differences in the larval fish community through space and time. For example, the abundance of temperate species in northern Baja California was relatively low when warm-water El Niño conditions prevailed in 1998 but increased during the cool-water La Niña period in 1999 and 2000. The results enhance knowledge of the community dynamics of fishes in an ecologically complex and commercially important region.

Monitoring of reef associated and pelagic fish communities on Australia’s first purpose built offshore artificial reef

2016 ◽  
Vol 74 (1) ◽  
pp. 277-285 ◽  
Author(s):  
Alistair Becker ◽  
Matthew D. Taylor ◽  
Michael B. Lowry
Keyword(s):  
Fish Assemblage ◽  
Monitoring Program ◽  
Artificial Reef ◽  
Integrated Approach ◽  
Artificial Reefs ◽  
Fish Length ◽  
Reef Fish Assemblage ◽  
Length Data ◽  
Natural Reefs ◽  
Term Monitoring

Artificial reefs now form part of an integrated approach to enhance fisheries around the world. A responsible approach to artificial reef deployment calls for clear, well defined goals prior to any reef being placed in the field, followed by subsequent monitoring to assess whether these goals are being achieved. In this study, to evaluate if an artificial reef off Sydney was meeting its goal of providing quality fishing opportunities through the establishment of a complex fish assemblage, a 4-year monitoring program was designed. This program examined the response of reef-associated and pelagic fishes to the deployment of a purpose built offshore reef, relative to control reefs. Fish were observed immediately following deployment, but the artificial reef fish assemblage remained distinct from the three natural control reefs throughout the monitoring period. Also, the artificial reef displayed inter-annual variability associated with successional processes, which was not evident on the natural reefs. Fish length data indicated that the artificial reef was providing resources for both juvenile and adults of a number of species. This study demonstrates artificial reefs can provide habitats for a diverse group of fish, but the assemblages are unlikely to mimic those on natural reefs. We have also shown that longer term monitoring periods, covering multiple years are required to gain a robust understanding of the response of fish to reef deployment. This information can be used to understand the benefits and limitations of future artificial reef deployments.

scholarly journals Induced sterility in fish and its potential and challenges for aquaculture and germ cell transplantation technology: a review

Biologia ◽  
2016 ◽  
Vol 71 (8) ◽  
Author(s):  
Amin Golpour ◽  
Mohammad Abdul Momin Siddique ◽  
Diógenes Henrique Siqueira-Silva ◽  
Martin Pšenička
Keyword(s):  
Germ Cell ◽  
Cell Transplantation ◽  
Large Scale ◽  
Hormonal Treatment ◽  
Important Species ◽  
Genetic Ablation ◽  
Germ Cell Transplantation ◽  
Commercially Important ◽  
Alternative Approaches ◽  
Hormone Signalling

AbstractInterest in reproductively sterile fish in aquaculture has prompted research into their production. Several methods are available for inducing sterility and optimizing its application in the global fishery industry. Sterilization can potentially be accomplished through irradiation, surgery, or chemical and hormonal treatment. Alternative approaches include triploidization, hybridization, and generation of new lines via advanced biotechnological techniques. Triploids of many commercially important species have been studied extensively and have been produced on a large scale for many years. Novel approaches, including disruption of gonadotropin releasing hormone signalling and genetic ablation of germ cells, have been developed that are effective in producing infertile fish but have the disadvantage of not being 100% reliable or are impractical for large-scale aquaculture. We review currently used technologies and recent advances in induction of sterility in fish, especially those intended for use in germ cell transplantation. Knowledge of the implications of these approaches remains incomplete, imposing considerable limitations.

Do changes in reef habitats influence relative predation risk on the juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875)?

Crustaceana ◽  
2015 ◽  
Vol 88 (7-8) ◽  
pp. 839-856 ◽  
Author(s):  
J. Hesse ◽  
J. A. Stanley ◽  
A. G. Jeffs
Keyword(s):  
Predation Risk ◽  
Spatial Scales ◽  
Spiny Lobster ◽  
Habitat Type ◽  
Small Spatial Scale ◽  
Important Species ◽  
Early Juvenile ◽  
Risk Of Predation ◽  
Jasus Edwardsii ◽  
Commercially Important

Kelp habitats are in decline in many temperate coastal regions of the world due to climate change and expansion of populations of grazing urchins. The loss of kelp habitat may influence the vulnerability to predators of the juveniles of commercially important species. In this study relative predation rates for kelp versus barren reef habitat were measured for early juvenile Australasian spiny lobster, Jasus edwardsii (Hutton, 1875), on the northeastern coast of New Zealand using tethering methods. Variation in assemblages of predators over small spatial scales appeared to be more important for determining the relative predation of lobsters, regardless of habitat type. Therefore, the assessment of relative predation risk to early juvenile lobsters between kelp and barren habitats will require more extensive sampling at a small spatial scale, as well as a specific focus on sampling during crepuscular and nocturnal periods when these lobsters are most at risk of predation.

scholarly journals Feeding of the Brycon cephalus, Triportheus elongatus and Semaprochilodus insignis (osteichthyes, characiformes) larvae in Solimões/Amazonas River and floodplain areas.

2002 ◽  
Vol 32 (3) ◽  
pp. 499-499 ◽  
Author(s):  
Rosseval Galdino LEITE ◽  
Carlos A.R.M. ARAUJO-LIMA
Keyword(s):  
Food Item ◽  
Prey Size ◽  
Larval Fish ◽  
Fish Larvae ◽  
Trophic Relations ◽  
Fish Feeding ◽  
Important Species ◽  
Flooded Forests ◽  
Commercially Important

Information on larval fish feeding is essential for understanding their trophic relations, including the management in conditions totally or partially controlled by humans. An experiment was designed to evaluate the larval diets of three commercially important species. Four varzea-lakes and the adjacent river were sampled with bongo and hand nets from January 1993 to November 1995. Larval diets were evaluated by length-classes and capture sites, and were tested by two factor ANOVA. The larvae were feeding in all habitats, except in the flooded forests. The three species had different diets, which varied with their length and lake. The rotifers were the main initial food item of the three species, replaced by fish larvae in Brycon cephalus, cladocerans in Triportheus elongatus and detritus in Semaprochilodus insignis. The increase of the ingestion limit, as the larvae grew, was higher than the increase in the consumed prey size for the three species.

Possible impacts of zoosporic parasites in diseases of commercially important marine mollusc species: part I. Perkinsozoa

2017 ◽  
Vol 60 (4) ◽  
Author(s):  
Frank H. Gleason ◽  
Osu Lilje ◽  
Cecile Dang ◽  
Sabrina Geraci-Yee ◽  
Jackie L. Collier
Keyword(s):  
Important Species ◽  
Marine Mollusc ◽  
Mollusc Species ◽  
Commercially Important

AbstractThe phylum Perkinsozoa includes well-known parasites of commercially important species of molluscs in aquaculture, such as

scholarly journals REDUCTION OF WAVE OVERTOPPING RATE BY THE USE OF ARTIFICIAL REEFS

1988 ◽  
Vol 1 (21) ◽  
pp. 23
Author(s):  
Toru Sawaragi ◽  
Ichiro Deguchi ◽  
San-Kil Park
Keyword(s):  
Wave Breaking ◽  
Artificial Reef ◽  
Numerical Procedure ◽  
Artificial Reefs ◽  
Irregular Waves ◽  
Analysis Method ◽  
Wave Analysis ◽  
Wave Overtopping ◽  
Unidirectional Flow ◽  
Individual Wave

A wave overtopping rate from a sea dike of various toe depths is formulated based on a weir model in an unidirectional flow. To evaluated the wave overtopping rate from a seadike on an artificial reef by the weir model, a numerical procedure for predicting wave transformations including the effect of forced wave breaking on the reef is constructed. After confirming the applicability of the model through experiments with regular and irregular waves, the effect of artificial reef on wave overtopping is discussed. So-called individual wave analysis method is shown to he applicable to the wave overtopping caused by irregular waves.

Artificial maturation, fertilization, and early development of the American eel (Anguilla rostrata)

2010 ◽  
Vol 88 (11) ◽  
pp. 1121-1128 ◽  
Author(s):  
K. Oliveira ◽  
W. E. Hable
Keyword(s):  
Early Development ◽  
Anguilla Rostrata ◽  
Sargasso Sea ◽  
American Eel ◽  
Important Species ◽  
Vitro Fertilization ◽  
Commercially Important ◽  
Elusive Species ◽  
American Eels

Spawning for the American eel ( Anguilla rostrata (Le Sueur, 1817)) takes place in secretive locations within the Sargasso Sea, which has thus far prevented investigations of gametogenesis and early development in this ecologically and commercially important species. Attempts to induce maturation and reproduction in this species have been few and have produced limited results, with a single report of the production of gastrula-stage embryos. Here we report the successful maturation of female American eels. Maturation occurred within 13 weeks and ovulation was induced with a single injection of 17α,20β-dihydroxy-4-pregnen-3-one (DHP). Following in vitro fertilization, embryogenesis through hatching was observed and larvae were maintained for up to 6 days. We show that a crucial factor for successful fertilization is the stage of the oocyte at the time of induced ovulation. Oocytes that had not reached the migratory nucleus stage, or had passed this stage, were not successfully fertilized. These findings demonstrate that American eel can reproduce in the laboratory and previously untestable hypotheses pertaining to the developmental biology of this elusive species can now be explored.

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