Recent human‐induced salinity changes in Ramsar‐listed Orielton Lagoon,south‐east Tasmania,Australia: a new approach for coastal lagoon conservation and management

• 1. Many coastal lagoons in eastern Australia have changed as a result of recent human activities. However, it is often difficult to determine the extent of change and the ecological implications. A palaeoecological approach allows a quantitative assessment of how an aquatic ecosystem changes and responds to human impacts beyond what is possible with historical data or monitoring programmes.
• 2. Orielton Lagoon (south‐east Tasmania, Australia) is a Ramsar‐listed coastal wetland of international importance for conservation. This study was undertaken at the site to determine whether recent anthropogenic hydrological modifications to the lagoon had influenced its ecology, particularly salinity, and compromised its Ramsar status.
• 3. A diatom–salinity transfer function was constructed from a training data set of 96 diatom taxa from 34 sampling sites in 19 lagoons along the east coast of Tasmania.
• 4. The salinity of Orielton Lagoon has changed in response to a causeway constructed across its mouth, which has transformed the lagoon from an open marine environment to an enclosed, virtually stagnant, brackish water body.
• 5. These changes have compromised the protected coastal wetland status of Orielton Lagoon. Environmental remediation attempts have since partially restored the natural hydrology of the lagoon and it is now returning towards the state it was in prior to causeway construction.
• 6. A palaeoecological approach using diatoms was found to be successful in reconstructing recent salinity changes and investigating human impacts on Orielton Lagoon over the last 50–55 years.

Copyright © 2006 John Wiley & Sons, Ltd.     

Field investigations and multi‐indicators for shallow water lagoon management: perspective for societal benefit

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Seasonality of hydrographic variables in a coastal lagoon: Mar Chiquita,Argentina

• 1. The concentration and distribution of several hydrographical variables from Mar Chiquita coastal lagoon, Argentina, were measured monthly over a year in order to quantify their seasonal variations. Temperature, salinity, inorganic nutrient concentrations (nitrate, nitrite, phosphate, silicate) in the water column, and photosynthetic pigments (chlorophyll a and phaeopigments) in suspended particulate matter (SPM), were measured using internationally standardized analytical methods.
• 2. Agricultural use of land surrounding the coastal lagoon has been shown to be the main nutrient source, owing to the use of fertilizers for farming and the consequent leaching of the soils by freshwater runoff.
• 3. Two different hydrographical areas were identified within the coastal lagoon, one showing marine influence and the other dominated by inland influence (due to catchment and freshwater inputs), both with different characteristics and ecological behaviour.
• 4. The frequent occurrence of phytoplankton blooms has also been identified within the coastal lagoon. There was significant biological production (in terms of chlorophyll a) within the lagoon throughout the year. The lagoon appears to function as a transitional system, opportunistically benefiting from extra nutrient inputs which, together with other environmental conditions, results in a continuous food supply, useful to both marine and estuarine organisms. Consequently the system is important for numerous fish and shellfish species as a nursery area.

Copyright © 2005 John Wiley & Sons, Ltd.     

The HELCOM system of a vision,strategic goals and ecological objectives: implementing an ecosystem approach to the management of human activities in the Baltic Sea

• 1. Since signing the Helsinki Convention in 1974, the countries with coasts around the Baltic Sea have striven jointly within the Helsinki Commission (HELCOM) towards the ecological restoration of the Baltic Sea. The European Community signed the revised Convention in 1992.
• 2. Work under HELCOM includes implementing joint recommendations to curb pollution originating from land and marine sources, ensuring safer maritime traffic, and protecting biodiversity, for example, by setting up a network of Baltic Sea protected areas.
• 3. A new concept — the ecosystem approach to the management of human activities — was adopted by the Contracting Parties of HELCOM in 2003 to serve as the new framework for further efforts towards attaining good ecological status of the Baltic Sea.
• 4. Stepwise progress towards the development of quantitative definitions of good ecological status has been made since 2003 to implement the new approach: a common vision reflecting the ecosystem approach was adopted in 2004 and a number of more targeted goals and objectives were agreed in 2006.
• 5. The Contracting Parties to the Helsinki Convention will use the objectives adopted covering eutrophication, impacts of hazardous substances, and the overall status of biodiversity, including the impact of fisheries and shipping, to draft a new set of joint management actions.
• 6. In the future, an agreement under development among the Contracting Parties on indicators with quantitative targets will enable a quantitative assessment of ‘good ecological status’ and progress towards the goals of HELCOM, the Convention on Biological Diversity (CBD), as well European legislation concerning marine environmental protection.

Copyright © 2007 John Wiley & Sons, Ltd.     

Estuarine eutrophication in the UK: current incidence and future trends

• 1. Increased inputs of nutrients to estuaries can lead to undesirable effects associated with eutrophication, including algal blooms, changes in species composition and bottom anoxia. Several estuaries and coastal areas around the UK have increased nitrogen (N) and phosphorus (P) concentrations, elevated concentrations of chlorophyll a and changes in algal community composition and abundance. This paper reviews the pressures that lead to high nutrient concentrations in estuaries and considers the likely effectiveness of current and proposed regulatory actions.
• 2. The main sources of nutrients to estuaries are river runoff, sewage discharges, atmospheric inputs and possibly submarine groundwater discharges, although little is known about the latter. Significant reductions in N and P inputs have been realized following application of the EU's Urban Waste Water Treatment Directive. Atmospheric NO_x and NH_x emissions have also decreased and are expected to decrease further in the next decade as implementation of existing legislation continues, and new controls are introduced for activities such as shipping.
• 3. Agricultural inputs reach estuaries principally through diffuse sources, either in surface water (and in some areas possibly groundwater) or, for N, via the atmosphere. Over 10 years ago the Nitrates Directive was introduced to tackle the problem of N discharges from agriculture but little change in N loads to estuaries has been recorded.
• 4. To meet the aims of the EU Water Framework Directive, for at least ‘good’ ecological status, more rigorous application and implementation of the Nitrates Directive, together with changes in the Common Agriculture Policy and farming practice are likely to be needed. Even then, the slow response of the natural environment to change and the inherent variability of estuaries means that their responses may not be as predicted. Research is needed into the relationship between policy drivers and environmental responses to ensure actions taken will achieve the planned results.

Copyright © 2008 John Wiley & Sons, Ltd.     

Determining keystone species complexes and macroscopic properties for improving ecosystem‐based conservation practices in coral reefs along the western Caribbean Sea (Mexico and Honduras)

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Notes on coastal lagoon typology in the light of the EU Water Framework Directive: Italy as a case study

• 1. The European Water Framework Directive (WFD) requires that Member States differentiate the transitional water bodies into types.
• 2. WFD assigns coastal lagoons to two different water categories, ‘transitional waters’ and ‘coastal waters’ on the basis of freshwater influence.
• 3. The main physical factors that contribute to the genesis and characterization of coastal lagoons are coastal typology, tidal range and climate.
• 4. Italian lagoons are presented as an example of how these physical factors can be used in coastal lagoon characterization and typology. On this basis, a clear distinction of Italian lagoons into two main groups is possible: Northern Adriatic and Mediterranean.
• 5. Large lagoons can be profitably subdivided into a hierarchical system of sub‐basins facilitating both the comparison of parts of the same lagoon and the comparison between different lagoons.
• 6. The basins are consistent water bodies that can be used as managerial units for environmental conservation, species protection and wise use of resources.

Copyright © 2006 John Wiley & Sons, Ltd.     

Rescue and relocation of benthic organisms during an urban‐port development project: Port of Manzanillo,case study

1. The present study originated with the expansion of the boardwalk within the urban and port area of Manzanillo, México. Prior to civil works related to the placement of tetrapods, surveys of potential sites for the relocation of benthic organisms in alternative areas were carried out.
2. Based on indicators of the physical–chemical environment and biotic factors, nine areas with potential for relocation were evaluated. The areas of greatest potential were associated with environments located away from the influence of the port environment.
3. A total of 13,559 benthic organisms belonging to 68 species associated with three main substratum types (rocky, sandy, and mixed) were collected. There were no differences in the ecological indices between the three substrata.
4. The proximity of the collection area to the influence of port traffic and sources of pollution associated with the physical environment could be an important factor that affects ecological indices and the reduction in the abundance of some protected species and species of commercial interest.
5. The success of collection and relocation processes depends on minimizing possible errors, especially during transportation, when overcrowding, handling, and damage resulting from variable physico‐chemical conditions should be avoided.
6. Through a scheme of actions based on ecological principles, management actions, and civil engineering technology, it was possible to carry out mitigation, conservation, and habitat improvement actions in coastal marine environments exposed to anthropogenic impacts.

     

Integrating pelagic and coastal MPAs into large‐scale ecosystem‐wide management

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Spatial differences across the French Pyrenees in the use of local habitat by the endangered semi‐aquatic Pyrenean desman (Galemys pyrenaicus)

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Marine protected areas in southern China: Upgrading conservation effectiveness in the ‘eco‐civilization’ era

1. ensuring that marine systems are not overwhelmed within the new national jurisdiction, and maintaining and enhancing marine capacity;
2. increased resourcing, supported by comprehensive and systematic economic valuations of ecosystem goods and services and natural capital;
3. upgraded enforcement of existing environmental laws and regulations, combined with further refinement and development, especially around cumulative impact management;
4. a particular focus on major reduction in water pollution in all forms;
5. integration of marine management between Hong Kong SAR and surrounding Guangdong Province; and
6. enhanced community engagement, participation and education.
7. Finally, much greater, collaborative engagement by the international community with Chinese marine management and conservation would bring major, and very mutual, benefits.

     

Long‐term habitat loss in a lightly‐disturbed population of the Indo‐Pacific humpback dolphin,Sousa chinensis

1. Coastal and estuarine waters are important ecosystems with high primary and secondary productivity, but they are prone to the impacts of habitat loss caused by anthropogenic activities. For species exclusively inhabiting coastal and estuarine waters, such as the Indo‐Pacific humpback dolphin, Sousa chinensis , irreversible habitat loss can have dramatic implications for population viability.
2. A Landsat image database was used to determine the extent of coastal changes along the northern Beibu Gulf, where a large humpback dolphin population is found. The results were compared with the standardized sighting gradient (SPUF) determined from a questionnaire survey of fishermen and likely core habitats identified by application of a global digital elevation model.
3. Both SPUF and likely core habitat results indicated a continuous distribution of the humpback dolphin along the northern Beibu Gulf. Landsat images revealed that 129.6 km² of coastal waters were permanently lost in the past 40 years, 60 km² within the likely core habitats. Although this may be considered small, the impact of such habitat loss could be substantial in some local habitats.
4. The humpback dolphin population in the northern Beibu Gulf should be regarded as one management unit, with two or more social subunits. Immediate systematic surveys are needed to fill information gaps on true distribution range and habitat‐use patterns.
5. Habitat protection actions for dolphins in the northern Beibu Gulf should include both core and linking habitats, including enacting protected areas in core habitats, mitigating anthropogenic impacts in likely habitats, restoring both coastal waters and surrounding landscape quality, effective treatment of industrial sewage discharge, and comprehensive environmental impact assessments for the planning of coastal development projects.

     

Conservation of a permanent hypersaline lake: management options evaluated from decadal variability of Coleofasciculus chthonoplastes microbial mats

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Linking pipefishes and seahorses to seagrass meadows in the Venice lagoon: Implications for conservation

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Water levels in a highland lake control the quantity and quality of spawning habitat for a littoral‐spawning galaxiid fish

1. In comparison with other habitats, the littoral zone can be disproportionately important to lentic fishes, especially for species that rely on it for reproduction. Impoundment of lentic waters can alter hydrological regimes, littoral inundation patterns and hydrodynamic processes, which can affect the quantity and quality of littoral habitats.
2. This study examined the effects of water‐level fluctuations on the quantity and quality of rocky littoral spawning habitat for the threatened Galaxias auratus in the Crescent–Sorell lake system, Tasmania (Australia) using GIS analyses, sediment measurements and observations of the composition and condition of littoral substrates under varying hydrological conditions.
3. The extent of littoral rocky substrate was found to be limited in Lake Crescent (<1.3% of the lake's bed). The relationship between water levels and G. auratus spawning habitat (littoral rocky substrates at depths of 0.2–0.6 m) was non‐linear with spawning habitat quantity and quality declining markedly at water levels <802.20 m Australian Height Datum (AHD). Hydrological impacts of global climate change on the Crescent–Sorell lake system are likely to increase the occurrence of water levels below this threshold in Lake Crescent in the future, thereby limiting the ability of G. auratus to sustain its population in this lake.
4. The structure of littoral areas of rocky substrate in Lake Crescent and Lake Sorell, and influential processes acting on these areas under varying hydrological conditions, were conceptualized to assist transferability of this knowledge to other lentic waters and species with similar habitat requirements.
5. Global climate change is predicted to alter lacustrine hydrological regimes and shoreline environments. This is likely to have significant ramifications for fishes that use littoral habitats during their life cycles, especially crucial reproductive phases. We believe the influence of alterations to hydrological regimes on the availability of these habitats to lacustrine fishes requires further investigation globally.

Copyright © 2016 John Wiley & Sons, Ltd.     

Assessment of the ecological status of north‐eastern Adriatic coastal waters (Istria,Croatia) using macroalgal assemblages for the European Union Water Framework Directive

• 1. Based on the inclusion of macroalgae in the European Union Water Framework Directive as quality elements for the evaluation of the ecological status of coastal waters, the suitability of one (Ecological Evaluation Index, EEI) of several previously proposed evaluation methods in the particular ecological conditions of the northern Adriatic Sea was tested.
• 2. The EEI was assessed for 10 locations (polluted and putatively pristine) scattered along 60 km of the western Istrian coast. The sampling was performed seasonally at 1 and 3 m depth by destructive (determination of species cover and biomass) and non‐destructive (determination of species coverage using digital photography) methods.
• 3. When assessed at 1 m depth the spatial scale weighted EEI for the west Istrian coast was 8.1, corresponding to an ecological status class (ESC) value of high. However, data for 3 m depth gave a spatial EEI of 6.72 which corresponds to an ESC value of good. Regressions of the ratio of ecological state group I (ESG I, i.e. thick leathery, calcareous and crustose species) over total algal abundance with the pollution gradient (obtained using principal components analysis (PCA) ordination of environmental variables) were significant at 3 m but not at 1 m depth. This was due to the high abundance of ESG I macroalgae Corallina elongata and Cystoseira compressa at 1 m depth at polluted stations. Similar regressions were obtained using cover, biomass and coverage.
• 4. It is concluded that the EEI method may be suitable for the classification of coastal waters in the northern Adriatic only in certain cases. A better assessment of ecological status using this method would require more realistic estimations based on the inclusion of data from several sampling depths. As all three abundance measures (cover, biomass, coverage) gave similar results, coverage (using digital photography) is suggested as being a preferred measure owing to the rapidity of sampling at several depths and less time‐consuming laboratory work.

Copyright © 2008 John Wiley & Sons, Ltd.     

Comparing the management effectiveness of a marine park and a multiple‐use collaborative fisheries management area in East Africa

• 1. The coral reefs across the international border between Kenya and Tanzania, where historical differences in government policy and socio‐economic conditions created two different management systems, were examined: a large permanent closed area and a collaborative fisheries management project that used gear management and small voluntarily and temporary closed areas, respectively. The diversity and ecology of the reefs in these two management systems were compared spanning a seven‐year period to evaluate the effectiveness of the management and to assess the ecological response to a large‐scale water‐temperature anomaly in 1998.
• 2. Comparisons of rates of predation on sea urchins and of herbivory, using a seagrass assay, were made along with measures of benthic cover and fish abundance and diversity.
• 3. The collaborative fisheries management system was successful in increasing fish stocks, reducing erect algae, and maintaining ecological diversity and stability across the thermal anomaly. This management system, however, was not successful in protecting the expected full biodiversity of fish, predation rates on sea urchins, or the sensitive, branching coral species. Management of the fishery also increased fish stocks in the adjacent, large, permanently closed area, compared to Kenyan parks without this management.
• 4. The large, permanently closed area in the other system maintained high diversity, high predation rates on sea urchins and high herbivory rates, which maintained erect algae abundance and diversity at low levels. The temperature anomaly was destructive to a number of the dominant delicate branching coral species, but overall coral cover and diversity were maintained, although dominance switched from branching Porites spp. to Seriatopora spp. over this period. The large closed area system protected the undisturbed ecology of these reefs and associated ecological processes, and the full diversity of fish and coral, including sensitive species such as branching corals and slow‐growing fish.
• 5. Collaborative fisheries and large permanent closed area management have different attributes that, when combined, should achieve the multiple purposes of sustainable fisheries, ecosystem functions and protection of fishing‐sensitive species.

Copyright © 2005 John Wiley & Sons, Ltd.     

What is the ecological footprint of aquaculture after 5 decades of competition between mangrove conservation and shrimp farm development?

1. Among the several threats to the conservation of mangrove ecosystems in most South Asian countries, shrimp farming is predominant. Since the introduction of shrimp farming in Sri Lanka in the 1980s, mangroves on the island’s north-western coast have been continually cleared to create new shrimp farms, leading to a decline in the social-ecological services provided by the mangrove ecosystems.
2. Using aerial (1973) and satellite (1996–2020) images, this study assessed areal changes in mangroves and shrimp farms in the Pambala-Chilaw lagoon complex and Ihala Mahawewa, as well as the ecological footprint of shrimp farming in the study area.
3. Mangroves around the Chilaw lagoon had decreased in areal extent by 45% from 1973 to 2020 of which 92% of this change was attributed to shrimp farming. There was, however, a decrease in the areal extent of shrimp farms from 2001 to 2020, and a corresponding increase in mangroves from 2006 to 2020.
4. The ecological footprint of shrimp farming was assessed by comparing the expected surface ratios with those recorded for shrimp farms with mangroves and surface water bodies in the study area from 1973 to 2020. The results showed that the current shrimp farming was unsustainable (i.e. high ecological footprint).
5. While the results support the current view that there is cause for cautious optimism with mangrove conservation (as evidenced by an increase in mangrove areal extent), it also reveals that semi-intensive shrimp farming in Sri Lanka and probably other similar tropical countries is unsustainable.
6. If immediate actions such as effective regulation of shrimp farming activities and mangrove restoration are not taken, the mangrove ecosystem will continue to decline.

     

Habitat protection actions for the Indo‐Pacific humpback dolphin: Baseline gaps,scopes, and resolutions for the Taiwanese subspecies

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