2,279 research outputs found

    Coastal and Marine Resource Condition Monitoring ā€“ Scoping Project: Final NRM Report ā€“ Project 073007

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    The marine and coastal environment of the Pilbara and Kimberley region in north-western Western Australia contains many assets, including remote and near pristine habitats, unique habitats within Australia, unique fauna and flora; as well as assets of value to commercial and industrial ventures; and for recreational human usage. However, there is a lack of monitoring in the Pilbara and Kimberley marine and coastal environments. This is in large part due to the remoteness of the area, making access difficult, and consequently making monitoring programs expensive to run in the region

    Development of Nutrient Criteria For Maineā€™s Coastal Waters

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    This report is submitted as required by Resolve 2007, chapter 49 enacted by the 123rd Maine Legislature, Resolve, Regarding Measures to Ensure the Continued Health and Commercial Viability of Maineā€™s Seacoast by Establishing Nutrient Criteria for Coastal Waters, and is presented to the legislatureā€™s Joint Standing Committee on Natural Resources. The full text of the enacted resolve is attached as Appendix A to this report

    Disturbance indicators for time series reconstruction and marine ecosystem health impact assessment

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    A systematic reconstruction of Multiple Marine Ecological Disturbances (MMEDs) involving disease occurrence, morbidity and mortality events has been undertaken so that a taxonomy of globally distributed marine disturbance types can be better quantified and common forcing factors identified. Combined disturbance data include indices of morbidity, mortality and disease events affecting humans, marine invertebrates, flora and wildlife populations. In the search for the best disturbance indicators of ecosystem change, the unifying solution for joining data from disparate fields is to organize data into space/time/topic hierarchies that permit convergence of data due to shared and appropriate scaling. The scale of the data selects for compatible methodologies, leading to better data integration, dine series reconstruction and the discovery of new relationships. Information technology approaches designed to assist this process include bibliographic keyword searches, data-mining, data-modeling and geographic information system design. Expert consensus, spatial, temporal, categorical and statistical data reduction methods are used to reclassify thousands of independent anomaly observations into eight functional impact groups representing anoxic-hypoxic, biotoxin-exposure, disease, keystone-chronic, mass-lethal, new-novel-invasive, physically forced and trophic-magnification disturbances. Data extracted from the relational database and Internet (http://www.heedmd.org) geographic information system demonstrate non-random patterns relative to expected dependencies. When data are combined they better reflect response to exogenous forcing factors at larger scales (e.g. North Atlantic and Southern Ocean Oscillation index scales) than is apparent without grouping. New hypotheses have been generated linking MMEDs to climate system forcing , variability and changes within the Northwestern Atlantic Ocean, Gulf of Mexico and Caribbean Sea. A more general global survey known collectively as the Health Ecological and Economic Dimensions (HEED) project demonstrates the potential application of the methodology to the Baltic Sea and other large marine ecosystems. The rescue of multi-decadal climatic, oceanographic, fisheries economic, and public health anomaly data combined with MMED data provides a tool to help researchers create regional disturbance regimes to illustrate disturbance impact. A recommendation for a central data repository is proposed to better coordinate the many data observers, resource managers, and agencies collecting pieces of marine disturbance information needed for monitoring ecosystem condition

    Spatial and temporal variability in water quality characteristics of the Swartkops Estuary

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    Water quality characteristics of the heavily urbanised and industrialised Swartkops River catchment in the Eastern Cape has been the focus of several studies since the 1970s. Overloaded and poorly maintained wastewater treatment works (WWTW), polluted stormwater runoff and solid waste have had a negative impact on the water quality status of the Swartkops River and estuary. Past studies have revealed that a distinct relationship exists between land use activities and the water quality of the Swartkops Estuary, which in turn has raised concerns pertaining to the ecological, economic, recreational, and cultural value of the estuaryThe Swartkops Estuary has a Present Ecological State (PES) of Category D(1) and a Recommended Ecological Category (REC)(2) of a C (Van Niekerk et al., 2014). It is known that effective management of anthropogenic impacts on coastal systems requires a thorough understanding of the systemā€™s biological responses to wastewater discharges and to hydrologic changes. For this reason, the objective of this study was to determine the current water quality status of the Swartkops Estuary, and to gain greater insight into factors controlling eutrophication. This was important as outdated water quality information was used in the Swartkops Integrated Environmental Management Plan (Enviro-Fish Africa, 2011) due to a lack of current data. To determine the current water quality status of the Swartkops Estuary the present study investigated spatial and temporal variability in physico-chemical parameters, nutrients, phytoplankton biomass and community composition, faecal bacteria, and ā€œwhere possibleā€ related this to historical water quality data. In general, points of entry into the estuary were investigated for their impact on nutrient enrichment and the bacteriological status of the estuary. Water quality surveys were completed in September 2012, November 2012, February 2013, May 2013 and August 2013The present study found evidence to suggest that water is not flushed as efficiently from the estuary as was previously the case, and that the natural hydrology of the estuary has been modified. These changes appear to be the effect of large volumes of wastewater discharges from the wastewater treatment works (WWTW), which has led to the additional stresses of increased vertical stratification and reduced vertical mixing. A build-up of dissolved inorganic nutrients has given rise to persistent eutrophic conditions and phytoplankton blooms occurring from the middle reaches to the tidal limit of the estuary. These findings were associated with a generally well oxygenated estuary; however, bottom water hypoxic conditions were recorded in the upper reaches of the estuary on two occasions and were generally associated with bloom.forming flagellates. Elevated concentrations of inorganic nutrients stimulated phytoplankton to attain high biomass ranging from 0 to 248 g l-1 (31.8 6.56 g l-1). All nutrients displayed positive linear gradients from the mouth to the tidal limit, showed significant (p 10 000 cells ml-1) of several different groups were recorded from the middle reaches of the estuary to the tidal limit. Diatoms were the dominant group during increased freshwater inflow (at mean daily flow rate of 2.14 m3 s-1) and low DIP levels, whereas flagellates were generally the dominant group during reduced flow and under higher nutrient levels. Although the different tidal stages had no effect on phytoplankton biomass per se, it did support co-existance between phytoplankton groups. This was noted during the spring ebb tide in September 2012 (i.e. flagellates, diatoms and dinoflagellate) and in February 2013 (i.e. dinoflagellates, diatoms and chlorophytes). Phytoplankton blooms have become persistent in the middle to upper reaches of the estuary where chlorophyll-a was > 20 Āµg l-1 and cell density exceeded 10 000 cells ml-1; a situation not reported in previous studies. The Motherwell Canal was and still is the main source of nitrogen (generally in the form of ammonium) to the estuary, whereas the Swartkops River is still the primary source of phosphorus to the estuary. Since the stormwater canal services the large residential area of Motherwell where leaks in the sewer system, the dumping of night soil buckets, and faulty pumps are often reported, polluted discharges from the Motherwell Canal can enter the canal at any given point. In contrast to the canal, DIP loading from the Swartkops River to the estuary generally occurred under conditions of low flow, whereas nitrogen showed no apparent relationship. Faecal bacteria originating from the Motherwell Canal had the most profound effect on the bacteriological status in the middle reaches of the estuary, whereas the Swartkops River had an intermediate effect due to bacteria die-offs occurring between the point of release from the WWTW to the riverine reaches and the tidal limit of the estuary. Nevertheless, Escherichia coli and enterococci levels are still high, especially in the summer months rendering the estuary unsafe for recreation during this season. Historical data on trace metals in the water column were limited and thus observations from the present study could not be concluded with much confidence. However, preliminary data suggest that levels of copper, zinc, iron and cadmium have increased by at least 90% in the estuary, at the tidal limit of the estuary and in the Markman and Motherwell canals. High inputs of nutrients, trace metals and faecal bacteria to the estuary from land-use activities indicate the necessity for remedial actions with the main objective being to conserve and protect the estuaryā€™s recreational, ecological and economic functions

    Assessing the impacts of seabed mineral extraction in the deep sea and coastal marine environments : Current methods and recommendations for environmental risk assessment

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    Mineral extraction from the seabed has experienced a recent surge of interest from both the mining industry and marine scientists. While improved methods of geological investigation have enabled the mapping of new seafloor mineral reserves, the ecological impacts of mining in both the deep sea and the shallow seabed are poorly known. This paper presents a synthesis of the empirical evidence from experimental seabed mining and parallel industries to infer the effects of seabed mineral extraction on marine ecosystems, focusing on polymetallic nodules and ferromanganese concretions. We use a problem-structuring framework to evaluate causal relationships between pressures caused by nodule extraction and the associated changes in marine ecosystems. To ensure that the rationale behind impact assessments is clear, we propose that future impact assessments use pressure-specific expert elicitation. We further discuss integrating ecosystem services in the impact assessments and the implications of current methods for environmental risk assessments.Peer reviewe

    Expert Review Group on Wetlands - combined report of the ERG

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