Fine‐scale diet of the Australian sea lion (Neophoca cinerea) using DNA‐based analysis of faeces          下载免费PDF全文

Kristian J. Peters  Kathy Ophelkeller  Nathan J. Bott  Bruce E. Deagle  Simon N. Jarman  Simon D. Goldsworthy 《Marine Ecology》2015,36(3):347-367

We applied DNA‐based faecal analysis to determine the diet of female Australian sea lions (n = 12) from two breeding colonies in South Australia. DNA dietary components of fish and cephalopods were amplified using the polymerase chain reaction and mitochondrial DNA primers targeting the short (~100 base pair) section of the 16S gene region. Prey diversity was determined by sequencing ~50 amplicons generated from clone libraries developed for each individual. Faecal DNA was also combined and cloned from multiple individuals at each colony and fish diversity determined. Diets varied between individuals and sites. Overall, DNA analysis identified a broad diversity of prey comprising 23 fish and five cephalopod taxa, including many species not previously described as prey of the Australian sea lion. Labridae (wrasse), Monacanthidae (leatherjackets) and Mullidae (goat fish) were important fish prey taxa. Commonly identified cephalopods were Octopodidae (octopus), Loliginidae (calamary squid) and Sepiidae (cuttlefish). Comparisons of fish prey diversity determined by pooling faecal DNA from several samples provided a reasonable but incomplete resemblance (55–71%) to the total fish diversity identified across individual diets at each site. Interpretation of diet based on the recovery of prey hard‐parts identified one cephalopod beak (Octopus sp.) and one fish otolith (Parapriacanthus elongatus). The present study highlights the value of DNA‐based analyses and their capabilities to enhance information of trophic interactions.  相似文献   

Relationships between land use and stream invertebrate community structure in a South Island,New Zealand,coastal stream catchment     

Matthew J. Hall  Gerard P. Closs  Ralph H. Riley 《新西兰海洋与淡水研究杂志》2013,47(3):591-603

Macroinvertebrate community composition was compared across streams draining catchments dominated by either native bush, agricultural or urban land uses within the Water of Leith stream catchment near Dunedin, New Zealand. Land use was associated with differences in taxon richness and faunal composition of communities present in each stream. The mean abundance levels of Ephemeroptera, Plecoptera, and Trichoptera were highest in native bush catchments, and lowest in urban catchments. In contrast, the mean abundance of Oligochaeta exhibited the opposite pattern. Increasing dominance of the urban and agricultural streams by pollution tolerant taxa was reflected in the Macroinvertebrate Community Index and Quantitative Macroinvertebrate Community Index scores.  相似文献   

Submarine groundwater discharge and benthic biogeochemical zonation in the Huanghe River Estuary     

Guangquan Chen  Bochao Xu  Shibin Zhao  Disong Yang  William C.Burnett  Shaobo Diao  Maosheng Gao  Xingyong Xu  Lisha Wang 《海洋学报(英文版)》2022,41(1):11-20

Submarine groundwater discharge(SGD) has received increasing attention by studies on coastal areas; however,its effects on biogeochemical zonation have not been investigated to date. The Huanghe River Estuary(HRE) is a world class river estuary with high turbidity, and heavy human regulation. This study investigated how SGD is related to the benthic biogeochemistry of the HRE. Based on the distribution of several parameters(e.g., salinity,temperature, dissolved oxygen(DO) levels, p H, radium iso...  相似文献   

Hog Daddy and the Walls of Steel: Catch Shares and Ecosystem Change in the New England Groundfishery     

Jennifer F. Brewer 《社会与自然资源》2014,27(7):724-741

The U.S. National Oceanic and Atmospheric Administration implemented market-based fishery management in the New England groundfishery as catch shares, controlling aggregate harvests through tradable annual catch quotas allocated to fishing groups called sectors. Policy supporters assert that resulting markets raise conservation incentives. In compliance with the Magnuson–Stevens Fishery Conservation and Management Act, species assessments permit catch shares to replace more spatially and temporally specific constraints on fishing gear, time, areas, and daily harvest limits. Qualitative evidence from field interviews and participant observation questions the efficacy of catch shares. Fishing industry members observe that increased presence of large trawl vessels in previously protected areas damages fish subpopulations and benthic habitat. Regulatory bioeconomic models fail to consider these lay observations. The consequent inability of quota markets to recognize the materiality of human–environment relationships at the spatiotemporal scales of fishing activity, and to internalize associated externalities, may have devastating consequences for the fishery.  相似文献   

The risk to New Zealand shellfish aquaculture from paralytic shellfish poisoning (PSP) toxins     

A. Lincoln MacKenzie 《新西兰海洋与淡水研究杂志》2014,48(3):430-465

New Zealand's reputation as a supplier of high quality food products is vital to the national economy; international consumers are acutely aware of food safety issues and markets are increasingly demanding higher standards. Filter feeding bivalves are particularly sensitive to the nature of the environment in which they are grown, and quality assurance is a major preoccupation of the shellfish aquaculture industry. With the exception of a couple of incidents, most notably the Gymnodinium catenatum blooms in 2000–2003, paralytic shellfish toxin (PST) contamination has, to date, not had an important effect on the economics and sustainability of the industry. However, the dinoflagellate species responsible for producing these toxins are not uncommon in New Zealand coastal phytoplankton communities, and it is important that awareness of the potential risk is maintained. This review summarises what we know about the causes and incidence of PST contamination from research and monitoring over the last 20 years, since it was first identified in New Zealand. It describes the dynamics of major events and their consequences, and evaluates what is likely to happen in the future as aquaculture expands into new areas with known histories of this problem.  相似文献   

Ammonites (Phylloceratina,Lytoceratina and Ancyloceratina) and organic-walled dinoflagellate cysts from the Late Barremian in Boljetin,eastern Serbia     

《Cretaceous Research》2014

Late Barremian ammonite fauna from the epipelagic marlstone and marly limestone interbeds of Boljetin Hill (Boljetinsko Brdo) of Danubic Unit (eastern Serbia) is described. The ammonite fauna includes representatives of three suborders (Phylloceratina, Lytoceratina and Ancyloceratina), specifically Hypophylloceras danubiense n. sp., Lepeniceras lepense Rabrenović, Holcophylloceras avrami n. sp., Phyllopachyceras baborense (Coquand), Phyllopachyceras petkovici n. sp., Phyllopachyceras eichwaldi eichwaldi (Karakash), Phyllopachyceras ectocostatum Drushchits, Protetragonites crebrisulcatus (Uhlig), Macroscaphites perforatus Avram, Acantholytoceras cf. subcirculare (Avram), Dissimilites cf. trinodosus (d'Orbigny) and Argvethites? sp. The taxonomic composition and percent abundance of the identified ammonites indicate that their taxa are predominantly confined to the Tethyan realm. Ammonites with smooth and slightly sculptured shells predominate among the studied fauna. The ammonite-bearing succession from Boljetin represents the lower part of the Upper Barremian, ranging in ammonite zonation from the Toxancyloceras vandenheckei Zone to the lower part of the Imerites giraudi Zone. The associated organic-walled dinoflagellate cysts confirm the Late Barremian age of the ammonite-bearing levels.  相似文献   

Spatial and temporal patterns in the hyperbenthic community structure in a warm temperate southern African permanently open estuary     

Elodie Heyns  William Froneman 《Estuarine, Coastal and Shelf Science》2010

The spatial and temporal patterns in the hyperbenthic community structure (>500 μm) in the warm temperate, permanently open Kariega Estuary situated along the south-eastern coastline of South Africa was investigated monthly over a period of twelve months. Data were collected using a modified hyperbenthic sledge at six stations along the length of the estuary. Physico-chemical data indicate the presence of a constant reverse salinity gradient, with highest salinities measured in the upper reaches and lowest at the mouth of the estuary. Strong seasonal patterns in temperature, dissolved oxygen and total chlorophyll-a (chl-a) concentration were evident. Total average hyperbenthic densities ranged between 0.4 and 166 ind.m⁻³ in the lower net and between 0.2 and 225 ind.m⁻³ in the upper net. Hyperbenthic biomass values ranged between 0.02 and 11.9 mg.dry weight.m⁻³ in the lower net and between 0.02 and 17.4 mg.dry weight.m⁻³ in the upper net. Both the lower and upper nets were numerically dominated by decapods (mainly brachyuran crab zoea) with the exception of June and July 2008 when mysids (mainly Mesopodopsis wooldridgei) dominated, comprising up to 72.4 ± 58.14% of the total abundance in the lower net. A redundancy analysis (RDA) indicated that 99.2% of the variance in the hyperbenthic community structure could be explained by the first two canonical axes. Axis one, which accounted for 96.8% of the total variation detected in the ordination plot was highly correlated with sedimentary organic content and to a lesser extent the chl-a concentration within the Kariega Estuary. The correlations with the second canonical axis (2.4%) were less obvious, however, salinity and seston concentration were weakly correlated with this axis.  相似文献   

STUDIES ON CULTURE CONDITIONS OF BENTHIC DIATOMS FOR FEEDING ABALONE Ⅲ. EFFECTS OF IRON AND SILICON NUTRIENTS AND OF ORTHOGONAL COMBINATIONS OF NITROGEN,PHOSPHORUS,IRON AND SILICON ON GROWTH RATE     

王起华  李雅娟  李梅 《中国海洋湖沼学报》1999,17(2)

rmDUCnONInthecultUreofbenthicdiatomsasfeedforabalone,itisnecesoptoaddsomnu-trientssuchasnitIngen,Phosphorus,ironandsilicontotheSeawatermwhum.Thecom-monraioofthenutrientswas(lO-25):(l-2.5):o.l:l(mg/L)(Chenetal.,1977).Anstinetal-(l99o)rePOrtedthatheratioofnibogenandphosphorusinfluencedthebio-massdensityofthePeriphyton,whichInainlyconsistedOfbenthicdiatomPOPulations.However,theirrestiltswerenotbasedonmonoalgalwwh,andtherewerenodetallsonthereasonableratioofthesenutrientsintheirreports-Ther…  相似文献   

Calibration and use of continuous heat-type automated seepage meters for submarine groundwater discharge measurements     

B.M. Mwashote  W.C. Burnett  J. Chanton  I.R. Santos  N. Dimova  P.W. Swarzenski 《Estuarine, Coastal and Shelf Science》2010

Submarine groundwater discharge (SGD) assessments were conducted both in the laboratory and at a field site in the northeastern Gulf of Mexico, using a continuous heat-type automated seepage meter (seepmeter). The functioning of the seepmeter is based on measurements of a temperature gradient in the water between downstream and upstream positions in its flow pipe. The device has the potential of providing long-term, high-resolution measurements of SGD. Using a simple inexpensive laboratory set-up, we have shown that connecting an extension cable to the seepmeter has a negligible effect on its measuring capability. Similarly, the observed influence of very low temperature (≤3 °C) on seepmeter measurements can be accounted for by conducting calibrations at such temperatures prior to field deployments. Compared to manual volumetric measurements, calibration experiments showed that at higher water flow rates (>28 cm day⁻¹ or cm³ cm⁻² day⁻¹) an analog flowmeter overestimated flow rates by ≥7%. This was apparently due to flow resistance, turbulence and formation of air bubbles in the seepmeter water flow tubes. Salinity had no significant effect on the performance of the seepmeter. Calibration results from fresh water and sea water showed close agreement at a 95% confidence level significance between the data sets from the two media (R² = 0.98). Comparatively, the seepmeter SGD measurements provided data that are comparable to manually-operated seepage meters, the radon geochemical tracer approach, and an electromagnetic (EM) seepage meter.  相似文献   

Historical changes in the structure and functioning of the benthic community in the lagoon of Venice     

Fabio Pranovi  Filippo Da Ponte  Patrizia Torricelli 《Estuarine, Coastal and Shelf Science》2008,76(4):1607

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