Fine-scale distribution of sardine (Sardina pilchardus) eggs and adults during a spawning event   总被引：2，自引：0，他引：2  

Juan Zwolinski  Evan Mason  Paulo B. Oliveira  Yorgos Stratoudakis 《Journal of Sea Research》2006,56(4):294-304

High-resolution acoustic and ichtyoplankton sampling with a ‘continuous under-way fish egg sampler (CUFES)’ was performed in two regions of approximately 100 square nautical miles off southern Iberian Peninsula, with the aim of studying the small scale distribution of sardine (Sardina pilchardus) adults and eggs during a spawning event. Very dense patches (246 eggs m^− 3) of recently spawned eggs with dimensions (up to 3 nautical miles wide) significantly larger than daytime sardine schools were present in both regions. Egg staging and ageing showed very little intra-sample variation, indicating a synchronous spawning period at dusk. The internal structure of the patches evaluated by variography showed very low internal variability, as if they consisted of a single unit. This hypothesis is confirmed by the acoustic finding of large sardine shoals with similar dimensions to those of the patches after sunset and throughout the night. During that period, adults were found near or in contact with the bottom, suggesting that spawning occurred at depth. A distinct patch of older eggs was found in both areas, but with a few nautical miles of horizontal separation. Their characteristics (a larger area, lower egg densities and a more irregular shape) indicate that these patches were exposed to dispersion and ‘stirring’ by physical forces, reshaping their initial appearance, while mesoscale water circulation could have displaced the core of the patches away by several kilometres within a day.  相似文献   

Preparation,Characterization of a Novel Chelating Resin Functionalized with o‐Hydroxybenzamide and Its Application for Preconcentration of Trace Metal Ions     

Aminul Islam  Akil Ahmad  Mohammad Asaduddin Laskar 《洁净——土壤、空气、水》2012,40(1):54-65

A stable extractor of metal ions was synthesized through azo linking of o‐hydroxybenzamide (HBAM) with Amberlite XAD‐4 (AXAD‐4) and was characterized by elemental analyses, IR spectral, and thermal studies. Its water regain value and hydrogen ion capacity were found to be 12.93 and 7.68 mmol g^?1, respectively. The optimum pH range (with the half‐loading time [min], t_1/2) for Cu(II), Cr(III), Ni(II), Co(II), Zn(II), and Pb(II) ions were 2.0–4.0 (5.5), 2.0–4.0 (7.0), 2.0–4.0 (8.0), 4.0–6.0 (9.0), 4.0–6.0 (12.0), and 2.0–4.0 (15.0), respectively. Comparison of breakthrough and overall capacities of the metals ascertains the high degree of column utilization (>70%). The overall sorption capacities for Cu(II), Cr(III), Ni(II), Co(II), Zn(II), and Pb(II) ions were found to be 0.29, 0.22, 0.20, 0.16, 0.13, and 0.11 mmol g^?1 with the corresponding preconcentration factor of 400, 380, 380, 360, 320, and 320, respectively. The limit of preconcentration was in the range of 5.0–6.3 ng mL^?1. The detection limit for Cu(II), Cr(III), Ni(II), Co(II), Zn(II), and Pb(II) were found to be 0.39, 0.49, 0.42, 0.59, 0.71, and 1.10 ng mL^?1, respectively. The AXAD‐4‐HBAM has been successfully applied for the analysis of natural water, multivitamin formulation, infant milk substitute, hydrogenated oil, urine, and fish.  相似文献   

Brominated flame retardants and organochlorine contaminants in winter flounder, harp and hooded seals, and North Atlantic right whales from the Northwest Atlantic Ocean     

Eric W. Montie  Robert J. Letcher  Michael J. Moore  Mark E. Hahn 《Marine pollution bulletin》2010,60(8):1160-1169

Various brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and current-use, non-PBDE BFRs, as well as organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs), were measured in winter flounder, harp and hooded seals, and North Atlantic right whales from the Eastern United States and Canada. The concentrations of PBDEs in winter flounder and right whales were similar in magnitude to the levels of PCBs, which was unlike the pattern observed in seals. In these marine mammals, the levels of PBDEs were orders of magnitude lower than the levels of OCs and PCBs detected. Evidence existed for the accumulation of methoxylated (MeO)-PBDEs of natural origin in seals and right whales. Current-use, non-PBDE BFRs (including hexabromocyclododecane, pentabromoethylbenzene, hexabromobenzene, and pentabromotoluene) were detected in winter flounder and marine mammals. Future research should focus on monitoring PBDEs, current-use, non-PBDE BFRs, and MeO-BDEs of natural origin in marine organisms from Massachusetts and Cape Cod Bays.  相似文献   

Post World War II orcharding creates present day DDT-problems in The Sørfjord (Western Norway) - A case study     

Anders Ruus  Norman W. Green  Carl Einar Amundsen  Jens Skei 《Marine pollution bulletin》2010,60(10):1856-1861

The Sørfjord has a long history of agriculture and industry, and environmental monitoring has been conducted for decades, comprising analyses of contaminants in mussel, fish and sediments. DDT was used as an insecticide in orchards surrounding the fjord between World War II and 1970. Since the early 1990s, elevated concentrations of DDT were found in mussels and fish. Unexpectedly, DDT-concentrations increased towards present day, despite the discontinuation of use. The highest concentrations in mussels (in 2006) corresponded to about two orders of magnitude higher than background. Analyses of sediment core sections also indicated increased input towards present day. Shifts in climatic parameters, as well as increased amounts of soil dissolved organic carbon following a decline in atmospheric sulphate deposition may have contributed to this phenomenon. We warrant the need for increased knowledge of the effects of alterations in variables acting regionally and globally on the disposition of contaminants in ecosystems.  相似文献   

Sea-surface microlayer toxicity off the Florida Keys     

D. Rumbold  S. Snedaker 《Marine environmental research》1999,47(5):1008

A survey of sea-surface microlayer (SSML) toxicity was initiated off the Florida Keys in early 1993. Ex situ toxicity tests, based on the development of the sea urchin, Lytechinus variegatus, demonstrated that 59.2% of SSML samples taken from visibly slicked areas (n=27) were toxic compared to collected subsurface water. A random subset of samples tested a second time using a fish early life-stage test with embryos from the spotted seatrout, Cynoscion nebulosus, confirmed the presence of the toxicant. Results from a partial toxicity identification evaluation (TIE) procedure indicated that an organic compound(s) containing a non-polar functional group was the primary determinant of toxicity in all of the SSML samples tested. While subsequent GC-MS analyses failed to identify a specific compound, they did tend to rule out common xenobiotics, such as organochlorine pesticides as potential toxicants. Preliminary tests, done by an outside laboratory, indicated that two of the most toxic SSML samples contained a brevetoxin, a biotoxin produced by Gymnodinium breve. This is the first report of natural toxins concentrating in the SSML; however, without a completed TIE, including a Phase III—toxicity confirmation procedure, the identification of any toxic agent remains speculative.  相似文献   

Discriminating sources of PCB contamination in fish on the coastal shelf off San Diego, California (USA)     

Ed Parnell P  Groce AK  Stebbins TD  Dayton PK 《Marine pollution bulletin》2008,56(12):1992-2002

Management of coastal ecosystems necessitates the evaluation of pollutant loading based on adequate source discrimination. Monitoring of sediments and fish on the shelf off San Diego has shown that some areas on the shelf are contaminated with polychlorinated biphenyls (PCBs). Here, we present an analysis of PCB contamination in fish on the shelf off San Diego designed to discriminate possible sources. The analysis was complicated by the variability of species available for analysis across the shelf, variable affinities of PCBs among species, and non-detects in the data. We utilized survival regression analysis to account for these complications. We also examined spatial patterns of PCBs in bay and offshore sediments and reviewed more than 20 years of influent and effluent data for local wastewater treatment facilities. We conclude that most PCB contamination in shelf sediments and fish is due to the ongoing practice of dumping contaminated sediments dredged from San Diego Bay.  相似文献   

Physiological responses of the seagrass Posidonia oceanica as indicators of fish farm impact     

Pérez M  García T  Invers O  Ruiz JM 《Marine pollution bulletin》2008,56(5):869-879

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Impact of fish farming on the distribution of phosphorus in sediments in the middle Adriatic area   总被引：1，自引：1，他引：0  

Matijević S  Kuspilić G  Kljaković-Gaspić Z  Bogner D 《Marine pollution bulletin》2008,56(3):535-548

During the last decade, intensive fish farming developed along the central Croatian coast, creating a need to study and evaluate its potential influence on unaffected sites. We considered phosphorus as an indicator of the influence of fish farming and investigated the distribution of phosphorus forms in sediment from several fish farms and marine areas of different trophic status in the middle Adriatic. Analyses of samples were performed with modified SEDEX techniques. Our results indicated that authigenic apatite phosphorus showed no significant differences among the investigated stations, while organic phosphorus concentrations reflected the trophic status of the station area. Below-cage sediment was characterized by enhanced fish debris phosphorus and low detrital apatite phosphorus concentrations, while sediment from an anthropogenically influenced bay showed the highest values of iron bound phosphorus species. Among the different P fractions, fish debris phosphorus proved to be the most sensitive indicator of the influence of fish farming on marine sediment.  相似文献   

Monitoring the sea change: preliminary assessment of the conservation value of nearshore reefs, and existing impacts, in a high-growth, coastal region of subtropical eastern Australia     

Smith SD  Rule MJ  Harrison M  Dalton SJ 《Marine pollution bulletin》2008,56(3):525-534

In northern NSW, Australia, coastal populations are forecast to increase dramatically over the next 25 years (the "sea change"). However, management of the effects of development on marine communities is hampered by the lack of data on key habitats. Consequently, we developed a protocol to assess the biodiversity and current human impacts on nearshore reefs, habitats that will be readily affected by coastal development. We assessed four reefs adjacent to each of three population centres targeting fish, mollusc and sessile benthic communities, and debris loads. Community structure was highly variable over all spatial scales indicating that reefs should not be considered equivalent within the planning framework. While, debris loads were relatively low on most reefs, those with highest conservation value also had the highest debris loads suggesting potential conflict between human use and long-term sustainability of reefal communities. Without intervention, this situation will be exacerbated in the future.  相似文献   

Fish mortality by impingement on the cooling-water intake screens of Britain's largest direct-cooled power station     

Greenwood MF 《Marine pollution bulletin》2008,56(4):723-739

An estimated 5.66 x 10(7) fish (summed quarterly 95% confidence intervals: 3.01 x 10(7)-1.07 x 10(8)) weighing 258.4 t (143.2-467.9 t) were killed on the cooling-water intake screens of the 2400 MW Longannet Power Station (Forth estuary) in January 1999--December 2000. Abundance and number of species (40) collected were close to predictions for a power station of this size and latitude. Potential losses of equivalent adult whiting (Merlangius merlangus), cod (Gadus morhua), and plaice (Pleuronectes platessa) through deaths of juveniles were estimated at 353.1 t (208.0-603.2 t) worth approximately euro 429,266 (euro 246,592-752,765) in 1999--2000. Fish catch-per-trawl in the estuary was generally not noticeably greater during a year of low water withdrawal (coal miners' strike of 1984--1985) when compared to other years from 1982 to 2001, except for gobies (Pomatoschistus spp.). A fish-return system is being tested at Longannet to reduce mortality.  相似文献