Distribution of seagrasses, and their fish and penaeid prawn communities, in Cairns harbour, a tropical estuary, Northern Queensland, Australia

1993 ◽  
Vol 44 (1) ◽  
pp. 193 ◽  
Author(s):  
RG Coles ◽  
WJ Lee Long ◽  
RA Watson ◽  
KJ Derbyshire
Keyword(s):  
Fish Species ◽  
Juvenile Fish ◽  
Dry Weight ◽  
Common Species ◽  
Shoot Density ◽  
Seagrass Beds ◽  
Commercial Fish ◽  
North Eastern ◽  
Commercial Species ◽  
Zostera Capricorni

From aerial photography (July 1987) and diving surveys (February 1988), 876 ha of seagrasses (eight species) were mapped in Cairns Harbour, tropical north-eastern Queensland. Zostera capricorni was the most common seagrass species and had the greatest biomass at 79 g m-2 dry weight of stems and leaves and 180 g m-2 dry weight of roots and rhizomes. The maximum shoot density found was 4798 shoots m-2 of Halodule pinifolia, the second most common species. Seagrasses were found only between 0.5 and 5.0 m below mean sea level. Zostera capricorni was found at the shallowest depths, Halodule pinifolia at the deepest depths. Twenty species of penaeid prawns, nine of which are marketed commercially, were sampled from the seagrass beds. Abundances of prawns of commercial species were significantly greater on seagrass-covered substrata than on nonvegetated substrata. Overall, 5614 mostly small or juvenile fish, representing 134 taxa, were sampled from seagrasses in Cairns Harbour. The most numerous fish species were a goby, Yongeichthys criniger, and a pony fish, Leiognathus splendens. Only 15 species were highly valued as recreational fish, and only 11 species were highly valued as commercial fish. Of the fish species, five (4%) were highly valued species of both groups. The density of fish on the seagrass beds was estimated to be 8809 fish ha-1.

scholarly journals Patterns of small fish distributions in seagrass beds in a temperate Australian estuary

2007 ◽  
Vol 87 (5) ◽  
pp. 1297-1307 ◽  
Author(s):  
Jane E. Jelbart ◽  
Pauline M. Ross ◽  
Rod M. Connolly
Keyword(s):  
Fish Species ◽  
Fish Assemblages ◽  
Juvenile Fish ◽  
Small Fish ◽  
Seagrass Beds ◽  
Estuary Mouth ◽  
Seagrass Cover ◽  
Australian Estuary ◽  
Continuous Beds ◽  
Zostera Capricorni

Beds of the seagrass Zostera capricorni are an integral part of the estuarine landscape along the east coast of Australia, forming an important habitat for juvenile fish. Seagrass beds can vary in their size, shape and patchiness of seagrass cover as well as their distance from the estuary mouth. We tested for a correlation between these features and small fish assemblages in seagrass. Fifteen beds were selected from three size-categories (small, 980 to 2300 m2; medium, 3375 to 4090 m2; and large, 5335 to 6630 m2). We found that the size of beds, the patchiness of seagrass cover and location within the estuary (distance from estuary mouth) were all related to differences in fish assemblages. There were greater densities of fish species in small (10.3 ±0.79 species .net-1) compared to medium (7.6 ±0.6) and large (8.2 ±0.5) beds. This occurred regardless of bed placement within the estuary, its patchiness or time of sampling (day and night). The fish assemblages within seagrass beds also changed as bed distance to estuary mouth increased. Six species had greater densities in beds closer to the estuary mouth, while only two species were in greater densities far from the mouth. Fish assemblages were different between beds with patchy and continuous cover, although total densities of all fish species combined were similar. There were greater densities of four species in continuous beds compared to two species that were greater in patchy beds. Overall, an important finding was that even small patchy seagrass beds contain greater densities of small fish species than larger beds with continuous seagrass cover.

scholarly journals Conservation-Status Gaps for Marine Top-Fished Commercial Species

Fishes ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 2
Author(s):  
Imanol Miqueleiz ◽  
Rafael Miranda ◽  
Arturo Hugo Ariño ◽  
Elena Ojea
Keyword(s):  
Fish Species ◽  
Conservation Status ◽  
Species Conservation ◽  
Biodiversity Loss ◽  
Vulnerability Index ◽  
Iucn Red List ◽  
Red List ◽  
Commercial Fish ◽  
Commercial Species ◽  
Marine Realm

Biodiversity loss is a global problem, accelerated by human-induced pressures. In the marine realm, one of the major threats to species conservation, together with climate change, is overfishing. In this context, having information on the conservation status of target commercial marine fish species becomes crucial for assuring safe standards. We put together fisheries statistics from the FAO, the IUCN Red List, FishBase, and RAM Legacy databases to understand to what extent top commercial species’ conservation status has been assessed. Levels of assessment for top-fished species were higher than those for general commercial or highly commercial species, but almost half of the species have outdated assessments. We found no relation between IUCN Red List traits and FishBase Vulnerability Index, depreciating the latter value as a guidance for extinction threat. The RAM database suggests good management of more-threatened species in recent decades, but more data are required to assess whether the trend has reverted in recent years. Outdated IUCN Red List assessments can benefit from reputed stock assessments for new reassessments. The future of IUCN Red List evaluations for commercial fish species relies on integrating new parameters from fisheries sources and improved collaboration with fisheries stakeholders and managers.

Growth and temperature relationships for juvenile fish species in seagrass beds: implications of climate change

2013 ◽  
Vol 84 (1) ◽  
pp. 231-236 ◽  
Author(s):  
D. J. Booth ◽  
D. E. Poulos ◽  
J. Poole ◽  
D. A. Feary
Keyword(s):  
Climate Change ◽  
Fish Species ◽  
Juvenile Fish ◽  
Seagrass Beds

scholarly journals Biological studies on the commercial juvenile fish of the eastern coast of Libya.

2018 ◽  
Author(s):  
Salma Husaien ◽  
Mohammed El.Mor. ◽  
Keyword(s):  
Food Habits ◽  
Juvenile Fish ◽  
Correlation Coefficients ◽  
Size Composition ◽  
Common Species ◽  
Eastern Coast ◽  
Feeding Intensity ◽  
Commercial Fish ◽  
Biological Studies ◽  
Feeding Activities

The structures of juvenile commercial fish in the shallow water of eastern coast of Libya, Mediterranean Sea were investigated. Size composition, fish abundance, length frequency distribution, length-weight relationships, condition factors and food habits of the most common species were studied. Lithognathus mormyrus juvenile dominated the catch from February till December and the recruitment appeared in February, November, and December. Liza carinata and Diplodus annularis appeared from April until November and the recruitment showed in April, Liza ramada was recorded from April till August and recruitment were in April. Salpa sarpa appeared from March till November and recruitment appeared from March till June, Lichia amia appeared from April till December and recruitment appeared in June. All the species illustrated significant Length-weight relationships with high correlation coefficients indicating isometric growth.The condition factors of Lithognathus mormyrus, Liza ramada, Lichia amia were similar, increasing as the size increased. The monthly variation in conditions was influenced by feeding activities. The highest values of condition factors appeared in autumn for all the species reached the maximum values by the end of spring except Liza ramada where the highest values were shown at the end of summer. The feeding intensity was higher and food habits were varied.

Seasonal feeding on Zostera capricorni seeds by Juvenile Penaeus esculentus (Crustacea: Decapoda) in Moreton Bay, Queensland

1990 ◽  
Vol 41 (2) ◽  
pp. 301 ◽  
Author(s):  
TJ Wassenberg
Keyword(s):  
Energy Content ◽  
Dry Weight ◽  
Seagrass Beds ◽  
Natural Diet ◽  
Food Items ◽  
Moreton Bay ◽  
Mean Size ◽  
Mature Seeds ◽  
Vegetable Material ◽  
Zostera Capricorni

The natural diet of juveniles of Penaeus esculentus Haswell (mean size 13.0 � 3.3 mm CL) collected from a seagrass (Zostera capricorni Aschers.) bed in Moreton Bay over 18 months was studied. There was a marked seasonal change in the occurrence of Z. capricorni seeds in their diet. These seeds made up to 1370 of the ash-free dry weight of the prawns' diet in November but disappeared completely from the diet between June and September. When seeds were not available, juvenile P. esculentus ate filamentous algae. Prawns less than 8 mm CL were not found with seeds in their foregut. There was no indication that prawns feed on seeds because of a shortage of other food items such as crustaceans or gastropods. Prawns studied in the laboratory removed seeds from the spathes and selected mature seeds. The seeds (each about 0.75 mg dry weight) had an energy content of 15.36 kJ g-1 dry weight. Seeds were found at densities of 456 m-2 in the seagrass beds. This study and other studies indicate that many species of juvenile penaeids incorporate vegetable material into their diet.

scholarly journals Polycyclic Aromatic Hydrocarbons (PAHs) in Muscles of Two Commercial Fish Species from Al-Kahlaa River in Missan Governorate, Iraq

2015 ◽  
Vol 20 (3) ◽  
pp. 121 ◽  
Author(s):  
Salih Hassan Jazza ◽  
Abdul-Hussain Y. Al-Adhub ◽  
Hamid T. Al-Saad
Keyword(s):  
Molecular Weight ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Fish Species ◽  
Aromatic Hydrocarbons ◽  
Dry Weight ◽  
Commercial Fish ◽  
Polycyclic Aromatic ◽  
Liza Abu ◽  
Oil Company ◽  
Total Concentrations

Al-Kahlaa River is one of main tributaries of the Tigris River in Missan city and rises from northwest side of Amara city and continues to flow in the direction to the east of city center. Two commercial fish species (Liza abu and Carassius auratus) were collected seasonally (autumn, winter, spring and summer) during period from 2012 to 2013 from Al-Kahlaa River in Missan governorate. The concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in fish muscles were determined in the laboratories of Nihran Omer (South Oil Company in Basrah province), using Gas Chromatography. Total concentrations of PAHs in muscles of L. abu ranged between 2.301 and 16.661 ng.g-1 dry weight during winter and summer respectively and in C. auratus between 1.095 and  8.675 ng.g-1 dry weight during winter and summer, respectively. Results of this study revealed that high molecular weight of PAHs were more than low molecular weight in both fish species, and according to ratios of Low molecular weight Polycyclic Aromatic Hydrocarbons (LPAHs) to High molecular weight Polycyclic Aromatic Hydrocarbons (HPAHs), Benzo(a) Anthracene /(Benzo(a) Anthracene+ Chrysene) BaA/(BaA+Chr),Indeno (1,2,3-cd) pyrene /(Indeno (1,2,3-cd) pyrene + Benzo (ghi) perylene) InP/(InP+BghiP) and Fluoranthene/Pyrene (Fl/Py), they certainly reflected that the PAHs sources in both species are pyrogenic as a main sources  and petrogenic as a small part. Also results of this study revealed the presence of seasonal variations in total concentrations of   PAHs in both fish species. The study area was generally contaminated with hydrocarbons and continuous consumption of food from this area may pose public health hazards. Keywords: polycyclic aromatic hydrocarbons, PAHs, fish, pollution Al-Kahlaa adalah salah satu anak sungai utama Sungai Tigris di kota Missan dari sisi barat laut kota Amara dan terus mengalir ke arah ke timur dari pusat kota. Dua spesies ikan komersial (Liza abu dan Carassius auratus) diperoleh pada musim berbeda (gugur, dingin, semi dan panas) selama periode 2012-2013 dari Al-Kahlaa. Konsentrasi polisiklik aromatik hidrokarbon (PAH) pada otot ikan dianalisis di laboratorium Nihran Omer (South Oil Company di provinsi Basrah), menggunakan Gas Chromatography. Total konsentrasi PAH pada otot L. abu berkisar antara 2,301 dan 16,661 ng.g-1 berat kering pada musim dingin dan musim panas. Sedangkan pada C. auratus antara 1,095 dan 8,675 ng.g-1 berat kering pada musim dingin dan musim panas. Hasil penelitian ini menunjukkan bahwa berat molekul tinggi PAH lebih dari berat molekul rendah pada kedua spesies ikan, dan menurut rasio berat molekul rendah polisiklik aromatik hidrokarbon (LPAHs) untuk berat molekul tinggi polisiklik aromatik hidrokarbon (HPAHs), Benzo (a ) Anthracene / (Benzo (a) Anthracene + Chrysene) BAA / (BAA + Chr), Indeno (1,2,3-cd) pyrene / (Indeno (1,2,3-cd) pyrene + Benzo (ghi) perylene) InP / (InP + BghiP) dan fluoranthen / Pyrene (Fl/Py), hal ini mencerminkan bahwa sumber PAH di kedua spesies adalah pirogenik sebagai sumber utama dan petrogenic sebagai bagian kecil. Hasil penelitian ini juga mengungkapkan adanya variasi musiman total konsentrasi PAH di kedua spesies ikan. Daerah penelitian umumnya terkontaminasi dengan hidrokarbon sehingga konsumsi makanan dari daerah ini secara berkelanjutan dapat menimbulkan bahaya kesehatan masyarakat. Kata kunci: polisiklik aromatik hidrokarbon, PAHs, ikan, polusi

scholarly journals Biological studies on the commercial juvenile fish of the eastern coast of Libya.

2018 ◽  
Author(s):  
Salma Husaien ◽  
Mohammed El.Mor. ◽  
Keyword(s):  
Food Habits ◽  
Juvenile Fish ◽  
Correlation Coefficients ◽  
Size Composition ◽  
Common Species ◽  
Eastern Coast ◽  
Feeding Intensity ◽  
Commercial Fish ◽  
Biological Studies ◽  
Feeding Activities

The structures of juvenile commercial fish in the shallow water of eastern coast of Libya, Mediterranean Sea were investigated. Size composition, fish abundance, length frequency distribution, length-weight relationships, condition factors and food habits of the most common species were studied. Lithognathus mormyrus juvenile dominated the catch from February till December and the recruitment appeared in February, November, and December. Liza carinata and Diplodus annularis appeared from April until November and the recruitment showed in April, Liza ramada was recorded from April till August and recruitment were in April. Salpa sarpa appeared from March till November and recruitment appeared from March till June, Lichia amia appeared from April till December and recruitment appeared in June. All the species illustrated significant Length-weight relationships with high correlation coefficients indicating isometric growth.The condition factors of Lithognathus mormyrus, Liza ramada, Lichia amia were similar, increasing as the size increased. The monthly variation in conditions was influenced by feeding activities. The highest values of condition factors appeared in autumn for all the species reached the maximum values by the end of spring except Liza ramada where the highest values were shown at the end of summer. The feeding intensity was higher and food habits were varied.

scholarly journals Determination of HeaDetermination of Some Heavy Metals in Three Fish Species from Duhok City Markets in Kurdistan of Iraq

2019 ◽  
Vol 7 (4) ◽  
pp. 152-157
Author(s):  
Shahyan S. Ahmed ◽  
Mahmood A. Hasan
Keyword(s):  
Heavy Metals ◽  
Fish Species ◽  
Inductively Coupled Plasma ◽  
Winter Season ◽  
Dry Weight ◽  
International Standards ◽  
Emission Spectrometry ◽  
Commercial Fish ◽  
Mean Values ◽  
Permissible Limits

In this study, the concentrations of some heavy metals including Al, Cu, Fe, Mn, Zn, Cd, Co, Cr, Ni and Pb were determined in the muscles of three commercial fish species available in Duhok city markets in two seasons, using inductively coupled plasma-optical emission spectrometry (ICP-OES), after the wet digestion process. Lowest and highest mean values of metals in µg/g (dry weight) were as follows: Al: Under Detection Limit (UDL)-3.71, Cu: UDL-4.00, Fe: 5.40-21.44, Mn: UDL-3.45, Zn: 13.38-140.11, while Cd, Co, Cr, Ni, and Pb were not detected. The highest levels of Al, Fe and Zn were recorded in Shukhat fish species, and the highest levels of Cu and Mn were recorded in Shabout in the winter season. The highest level of all metals was recorded for Zn (172.8 µg/g) with the highest mean value of (140.11 µg/g) in Shukhat species during winter.  Most heavy metal concentrations were below the international permissible limits for fish, however, some of the maximum and mean values of metals were above the international standards. Fe concentrations were above the maximum allowable limits set by WHO (1999). Zn concentrations were above the maximum permissible limits set by joint FAO/WHO (1989) and FAO (2012).

scholarly journals Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Agnes Robert ◽  
Prosper Mfilinge ◽  
Samwel M. Limbu ◽  
Chacha J. Mwita
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Human Health ◽  
Fish Species ◽  
Lake Victoria ◽  
Nile Perch ◽  
Commercial Fish ◽  
Tilapia Zillii ◽  
Significant Difference ◽  
Commercial Species

Fatty acids (FAs) particularlyω3 andω6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selectedω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus),Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and eicosatetraenoic acids.O. niloticushad the highest composition of FAs (34) compared toL. niloticus(27),T. zillii(26), andR. argentea(21). The levels of EPA differed significantly among the four commercial fish species(F=6.19,  P=0.001). The highest EPA levels were found inR. argenteafollowed byL. niloticusandO. niloticusand the lowest inT. zillii. The DPA levels showed no significant difference among the four fish species studied(F=0.652,  P=0.583). The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, butR. argenteais the best for consumption because it contains higher levels ofω3 FAs, mainly EPA.

scholarly journals Coherent trends in contiguous survey time-series of major ecological and commercial fish species in the Gulf of Maine ecosystem

2009 ◽  
Vol 67 (1) ◽  
pp. 26-40 ◽  
Author(s):  
Janet A. Nye ◽  
Alida Bundy ◽  
Nancy Shackell ◽  
Kevin D. Friedland ◽  
Jason S. Link
Keyword(s):  
United States ◽  
Time Series ◽  
Fish Species ◽  
Gulf Of Maine ◽  
Atlantic Cod ◽  
Ecological Factors ◽  
The United States ◽  
Common Species ◽  
Total Biomass ◽  
Commercial Fish

AbstractNye, J. A., Bundy, A., Shackell, N., Friedland, K. D., and Link, J. S. 2010. Coherent trends in contiguous survey time-series of major ecological and commercial fish species in the Gulf of Maine ecosystem. – ICES Journal of Marine Science, 67: 26–40. Fish are often delineated into distinct population or stock units that reflect human institutional borders more than ecological factors. In the Northwest Atlantic, there are many species in the broader Gulf of Maine area (GOMA), yet the area is surveyed and managed for the most part in the south by the United States and in the north by Canada. Biomass time-series of 19 representative fish species and total biomass from 7 different surveys conducted by the United States and Canada in the GOMA are compared. All species showed coherent trends in relative biomass across at least two survey time-series, and in many species a single trend could describe all time-series trends accurately. For instance, Canadian and the US time-series of Atlantic cod, Atlantic herring, haddock, thorny skate, and goosefish had comparable trends. Conversely, species such as longhorn sculpin and spiny dogfish showed differing survey time-series trends and asynchronous event timing, suggesting that their population dynamics differ spatially. Collectively, the results demonstrate the value of comparing time-series for common species from contiguous ecosystems and elucidate the relative importance of environmental and fishing factors on each species.

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