Marine Ecosystem Restoration Research Articles

Key food web technique and evaluation of nearshore marine ecological restoration of Bohai Bay

An ecological key food web restoration technique is proposed to restore the degraded nearshore marine ecosystem near the Bohai Bay, in which the key species are screened and the local key food web is built according to the trophic relationships of screening species to reference ecosystem. The trophic relationships of the key food web are quantified by the biomass of the screening species of each trophic level and the restoration input biomass is fixed. The restoration effect of the proposed technique on the restored ecosystem is predicted by the maturity and health with the Ecopath model and the ocean health index. The proposed technique is applied to the First Harbor of Tianjin Lin Gang Economic Zone. The calculated restoration effect shows that the restored (target) ecosystem is more mature, faster ecological balanced and healthier than the existing ecosystem. The ocean health index of the target ecosystem is 86.3, which is much higher than 51.8 of the existing ecosystem. It is concluded that the proposed technique is effective and applicable in the nearshore marine ecosystem restoration.

Does life history connectivity explain distributions of Chilean jack mackerel Trachurus murphyi caught in international waters prior to decline of the southeastern Pacific fishery?

In severely depleted stocks, biological data taken prior to fishery decline are invaluable as a reference for recovery; and to understand the spatial population structure, especially when connectivity crosses management boundaries over the life history. Prior to a precipitous decline from 2010, Chilean jack mackerel (Trachurus murphyi) showed strong cyclic migrations hypothesized to encompass coastal areas regulated by national authorities along western South America and unregulated international waters offshore. In a preliminary analysis, we present data taken in international waters between 2000 and 2003 by a program sampling commercial catches from Chinese trawlers. Overall, catch length distributions occupied fork length classes from 240mm to 600mm, with a modal length class of 320mm for females and 340mm for males and the weight-length relationship was BW=0.000 006 52FL3.0708. Males showed increasing predominance with length. Nearly 80% of fish had prey items in their stomachs; only 1% had full stomachs, suggesting that few fish were feeding intensively. However, mean fork length declined from 327mm to 259mm between 2000 and 2003, and population juvenescence as a result of exploitation may help explain these data. Nevertheless, adult spatial distributions were also consistent with migrations between feeding and spawning grounds. Distinguishing the spatial structure of such life history connectivity, and how it interacts with fishing activity, is critical to refining the conservation measures necessary to rebuild large oceanic fisheries and restore marine ecosystems.

Innovative methods of marine ecosystem restoration

Innovative methods of marine ecosystem restoration

Nearshore Drift-Cell Sediment Processes and Ecological Function for Forage Fish: Implications for Ecological Restoration of Impaired Pacific Northwest Marine Ecosystems

Parks, D.; Shaffer, A., and Barry, D., 2013. Nearshore drift-cell sediment processes and ecological function for forage fish: implications for ecological restoration of impaired Pacific Northwest marine ecosystems.Sediment processes of erosion, transport, and deposition play an important role in nearshore ecosystem function, including forming suitable habitats for forage fish spawning. Disruption of sediment processes is often assumed to result in impaired nearshore ecological function but is seldom assessed in the field. In this study we observed the sediment characteristics of intertidal beaches of three coastal drift cells with impaired and intact sediment processes and compared the functional metrics of forage fish (surf smelt, Hypomesus pretiosus, and sand lance, Ammodytes hexapterus) spawning and abundance to define linkages, if any, between sediment processes and nearshore ecological function. Key findings include: (1) beach sediment characteristics of the northern Washington nearshore are complex, with strong seasonal variation in habitat form and function both within and across geomorphic habitat types; (2) loss of sediment supply to the nearshore due to in-river damming and shoreline alterations results in significantly larger and more variable beach sediment at the drift-cell scale; (3) these differences in intertidal beach sediment characteristics have implications for habitat function as indicated by less forage fish spawning habitat and lower ecological function than intact drift cells; (4) feeder bluffs are important nearshore sediment sources for forage fish spawning beaches. Forage fish may spawn at the base of feeder bluffs if appropriate sediment is available during the spawning season; and (5) seasonal rate, total volume, and grain size of sediment delivery are important for habitat suitability for fish use. Feeder bluffs therefore should be managed more conservatively and understanding and protecting their role in nearshore habitat restoration practices is a high priority.

Global catches, exploitation rates, and rebuilding options for sharks

Adequate conservation and management of shark populations is becoming increasingly important on a global scale, especially because many species are exceptionally vulnerable to overfishing. Yet, reported catch statistics for sharks are incomplete, and mortality estimates have not been available for sharks as a group. Here, the global catch and mortality of sharks from reported and unreported landings, discards, and shark finning are being estimated at 1.44 million metric tons for the year 2000, and at only slightly less in 2010 (1.41 million tons). Based on an analysis of average shark weights, this translates into a total annual mortality estimate of about 100 million sharks in 2000, and about 97 million sharks in 2010, with a total range of possible values between 63 and 273 million sharks per year. Further, the exploitation rate for sharks as a group was calculated by dividing two independent mortality estimates by an estimate of total global biomass. As an alternative approach, exploitation rates for individual shark populations were compiled and averaged from stock assessments and other published sources. The resulting three independent estimates of the average exploitation rate ranged between 6.4% and 7.9% of sharks killed per year. This exceeds the average rebound rate for many shark populations, estimated from the life history information on 62 shark species (rebound rates averaged 4.9% per year), and explains the ongoing declines in most populations for which data exist. The consequences of these unsustainable catch and mortality rates for marine ecosystems could be substantial. Global total shark mortality, therefore, needs to be reduced drastically in order to rebuild depleted populations and restore marine ecosystems with functional top predators.

Milankovitch and sub-Milankovitch cycles of the early Triassic Daye Formation, South China and their geochronological and paleoclimatic implications

The mass extinction at the end of Permian was followed by a prolonged recovery process with multiple phases of devastation–restoration of marine ecosystems in Early Triassic. The time framework for the Early Triassic geological, biological and geochemical events is traditionally established by conodont biostratigraphy, but the absolute duration of conodont biozones are not well constrained. In this study, a rock magnetic cyclostratigraphy, based on high-resolution analysis (2440 samples) of magnetic susceptibility (MS) and anhysteretic remanent magnetization (ARM) intensity variations, was developed for the 55.1-m-thick, Early Triassic Lower Daye Formation at the Daxiakou section, Hubei province in South China. The Lower Daye Formation shows exceptionally well-preserved lithological cycles with alternating thinly-bedded mudstone, marls and limestone, which are closely tracked by the MS and ARM variations. Power spectral, wavelet and amplitude modulation (AM) analyses of the ARM and MS series reveal strong evidence for the presence of Milankovitch to sub-Milankovitch frequencies dominated by precession index signal and 4–5ka cycles. Cycles expressed by variations in MS and ARM were likely controlled by changes in the input of fine-grained detrital magnetite, which in turn may have been driven by astronomically induced changes in monsoon intensity in the equatorial eastern Paleotethys during the Early Triassic greenhouse period.On the basis of the 100-ka tuning results, the astronomically constrained duration of the Induan stage is 1.16Ma, with the Griesbachian and Dienerian substages of 490ka and 670ka, respectively. The new astronomical time scale also provides time constraints for the conodont and bivalve biozones and the carbonate carbon isotope (δ13C) records of the Lower Triassic Daye Formation. Time constraints for the conodont biozones include 34ka for Hindeodus parvus, 24ka for Isarcicella staschei–I. isarcica, 366ka for Neogondolella planata–Ng. carinata, 66ka for Neogondolella discreta, 255ka for Neospathodus kummeli and 415ka for Neospathodus dieneri. The duration for the negative δ13C shift from high δ13C values near the Indun/Olenekian boundary to the lowest value in the Early Smithian is estimated as 430ka. Global comparison indicates that Milankovitch and 4–5ka sub-Milankovitch forcing depositional rhythms may have been common in tropical and sub-tropical carbonate platforms during the Early and Middle Triassic time. The ultimate control on the 4–5ka cycles may have been millennial-scale fluctuations in solar insolation.

Comparing European Instruments for Marine Nature Conservation: The OSPAR Convention, the Bern Convention, the Birds and Habitats Directives, and the Added Value of the Marine Strategy Framework Direct

This article performs a comparative analysis of five major legal instruments for (marine) nature conservation in Europe, namely the 1979 Bern Convention on the Conservation of European Wildlife and Natural Habitats, the 1979 EU Wild Birds Directive, the 1992 EU Habitats Directive, the 1992 OSPAR Convention for the Protection of the Marine Environment of the North-East Atlantic, and the 2008 EU Marine Strategy Framework Directive (MSFD). Through this analysis, an answer is provided to the question what the recently added MSFD contributes to the pre-existing legal framework in the field of marine nature conservation. To provide the necessary focus, the analysis is carried out from the perspective of one marine subregion, the North Sea, although many elements of it are ostensibly of wider relevance. The article systematically explores the potential added value of the MSFD with regard to marine protected areas (MPAs) and other types of nature conservation measures. It concludes that the MSFD apparently contributes both substance and legal teeth to the legal framework for the protection, management and restoration of marine species, habitats and ecosystems in Europe.

Biomanipulation: a tool in marine ecosystem management and restoration?

Widespread losses of production and conservation values make large-scale ecosystem restoration increasingly urgent. Ecological restoration by means of biomanipulation, i.e., by fishing out planktivores to reduce the predation pressure on herbivorous zooplankton, has proved to be an effective tool in restoring degraded lakes and coastal ecosystems. Whether biomanipulation may prove a useful restoration method in open and structurally complex marine ecosystems is, however, still unknown. To promote a recovery of the collapsed stock of Eastern Baltic cod (Gadus morhua), large-scale biomanipulation of sprat (Sprattus sprattus), the main planktivore in the Baltic Sea, has been suggested as a possible management approach. We study the effect of biomanipulation on sprat using a statistical food-web model, which integrates internal interactions between the main fish species of the Central Baltic Sea, with external forcing through commercial fishing, zooplankton, and climate. By running multiple, stochastic simulations of reductions in sprat spawning stock biomass (SSB) only minor increases in cod SSB were detected, none of which brought the cod significantly above ecologically safe levels. On the contrary, reductions in cod fishing mortality and/or improved climatic conditions would promote a significant recovery of the stock. By this we demonstrate that an ecosystem-scale biomanipulation, with the main focus of reinstating the dominance of cod in the Baltic Sea may likely be ecologically ineffective, operationally difficult, and costly. We argue that reducing exploitation pressure on Eastern Baltic cod to ecologically sound levels is a far more appealing management strategy in promoting a long-term recovery and a sustainable fishery of the stock.

Trace fossil evidence for restoration of marine ecosystems following the end-Permian mass extinction in the Lower Yangtze region, South China

Unlike the high-abundance, low-diversity macrofaunas that characterize many Early Triassic benthic palaeocommunities, ichnofossils were relatively common in the aftermath of the end-Permian mass extinction worldwide. Ichnofossils therefore are a good proxy for ecosystem recovery after the end-Permian biotic crisis. This paper documents 14 ichnogenera and one problematic form from Lower Triassic successions exposed in the Lower Yangtze region, South China. Post-extinction ichnodiversity remained rather low throughout the Griesbachian–early Smithian period and abruptly increased in the late Smithian. However, several lines of evidence, including extent of bioturbation, burrow size, trace-fossil complexity, and tiering levels, indicate that diversification of ichnotaxa in the late Smithian did not signal full marine ecosystem recovery from the Permian/Triassic (P/Tr) mass extinction. Marine ichnocoenoses did not recover until the late Spathian in South China. The marginal sea provided hospitable habitats for tracemakers to proliferate in the aftermath of the end-Permian mass extinction.

Biomanipulation - a tool in Marine Ecosystem Management and Restoration?

Biomanipulation - a tool in Marine Ecosystem Management and Restoration?

The Rise of Restoration Ecology

![Figure][1] CREDIT: GRAND TOUR/CORBIS In art, restoration involves recapturing an object's aesthetic value. In ecology, the stakes are arguably much higher: Our planet's future may depend on the maturation of the young discipline of ecological restoration. In this issue, we sample restoration projects around the world and consider the state of the science of this emerging field. The goal of restoration ecology is not necessarily to restore an ecosystem to a pristine, prehuman ideal, but a long-term view is still important. In the opening Perspective, Jackson and Hobbs (p. [567][2]) highlight paleoecology as a component of restoration science. Two more Perspectives focus on aspects of terrestrial ecosystems that are vital to the success of restoration. Harris (p. [573][3]) considers the role of the soil microbial community: the bacteria and fungi that degrade organic matter and provide nutrients to the system. Dixon (p. [571][4]) highlights the role of pollinators, whose activities are essential to natural and restored plant communities. The struggle to balance ecosystem complexity and economic reality is the theme of three News features: two that examine efforts to restore functional forest ecosystems in southern China (p. [556][5]) and Borneo (p. [557][6]) and a third that probes the ecological consequences of burgeoning rubber plantations in Southeast Asia (p. [564][7]). How successful is restoration? In a Perspective, Palmer and Filoso (p. [575][8]) caution that it is unlikely to lead to the full recovery of the biodiversity and ecosystem services of undisturbed systems. A meta-analysis by Rey Benayas et al. , published on Science Express this week, confirms this view but shows that well-done restoration consistently enhances biodiversity and ecosystem services. In another Perspective, Norton (p. [569][9]) considers the limits to restoration posed by invasive species, and a News story examines the success of a national program targeting invasives in South Africa (p. [562][10]). Also on Science Express this week, Schulte et al. report an unprecedented restoration of oysters in the Chesapeake Bay in the eastern United States, which bodes well for the health of the entire estuarine ecosystem. Coral reefs, meanwhile, are under attack from human insults and climate change; a News feature (p. [559][11]) gives an overview of important efforts to restore damaged reefs. Finally, in a Research Article, Worm et al. (p. [578][12]) review current efforts to restore marine ecosystems and fisheries, concluding that making fisheries sustainable is an achievable goal. Restoration ecology is a relatively new science—the Society for Ecological Restoration International ([www.ser.org/default.asp][13]) celebrates its 21st birthday this year—but in its short life it has assumed a major role in sustainable development efforts across the globe. [1]: pending:yes [2]: /lookup/doi/10.1126/science.1172977 [3]: /lookup/volpage/325/573?iss=5940 [4]: /lookup/volpage/325/571?iss=5940 [5]: /lookup/doi/10.1126/science.325_556 [6]: /lookup/doi/10.1126/science.325_557 [7]: /lookup/volpage/325/564?iss=5940 [8]: /lookup/doi/10.1126/science.1172976 [9]: /lookup/volpage/325/569?iss=5940 [10]: /lookup/volpage/325/562?iss=5940 [11]: /lookup/volpage/325/559?iss=5940 [12]: /lookup/volpage/325/578?iss=5940 [13]: http://www.ser.org/default.asp

A Legal Study on Marine Ecosystem Restoration by Oil Pollution Damage

A Legal Study on Marine Ecosystem Restoration by Oil Pollution Damage

Early Triassic carbon isotope excursions from South China: proxies for devastation and restoration of marine ecosystems following the end‐Permian mass extinction

AbstractEarly Triassic carbon isotopes are measured based on 1422 carbonate bulk samples from 10 Lower Triassic sections in different palaeogeographic settings in South China. Early Triassic fluctuation ofδ13C is used as a proxy for environmental change to discuss the devastation and restoration of marine ecosystems following the biggest Phanerozoic mass extinction at the end of the Permian. Early Triassicδ13C profiles derived from various depositional settings in South China yield comparable excursion patterns. A dramatic negative shift ofδ13C across the Permian/Triassic boundary is followed by a moderate increase inδ13C values throughout the Induan. A positiveδ13C anomaly occurs near the Induan/Olenekian boundary, followed by a Smithian interval of lowerδ13C values. A distinct positive shift inδ13C coincides with the Smithian/Spathian boundary, and is followed by a high Spathian plateau ofδ13C values. Thus the distinctδ13C anomalies coincide well with key stratigraphic boundaries.Early Triassic intervals of lowδ13C values correspond to a decline in benthic generic diversity in South China and intervals of highδ13C values are coupled with an increase in biodiversity. The Early Triassic fluctuations ofδ13C profiles are good proxies for perturbations of ecologic environments, indicating multiple phases of devastation–restoration of marine ecosystems punctuated by several unexpected extraneous events such as volcanic activity. The initial restoration of marine ecosystems may have occurred earlier in the Induan and the ecosystems were subsequently destroyed during the Smithian. Biotic and environmental recoveries occurred at the Spathian, while the ecosystems eventually returned to normal levels in the early Middle Triassic. Copyright © 2007 John Wiley & Sons, Ltd.

Discounting, Amenity Values, and Marine Ecosystem Restoration

Colin Clark, during his wrap-up of the 2005 Biennial Forum of North American Fisheries Economists that took place at the University of British Columbia, Vancouver, Canada, challenged participants regarding discounting as a barrier to demonstrating the economic viability of ecosystem restoration. Through this contribution, we hope to initiate a conversation among marine resource economists on the role of discounting on ecosystem restoration and the long-term, sustainable management of marine resources. We relate the problem of discounting benefits of ecosystem restoration to that of valuing the amenities that restored ecosystems could produce, and suggest how empirical research might contribute to the debate over the proper discount rate to apply in valuing natural and ecosystem resources.

Assessing cause and effect of multiple stressors on marine systems

An operational framework is developed to serve as a guideline for investigating causal relationships between environmental stressors and effects on marine biota. Because of the complexity and variability of many marine systems, multiple lines of evidence are needed to understand relationships between stressors and effects on marine resources. Within this framework, a weight of evidence approach based on multiple lines of evidence are developed and applied in a sequential manner by (1) characterizing the study system which involves determining if target biota are impaired, assessment of food and habitat availability, and measuring contaminant levels in the environment, (2) assessing direct effects of contaminant exposure on target biota using biomarkers and assessing indirect effects of exposure using suites of bioindicators, and (3) applying standard causal criteria based on epidemiological principles and diagnostic health profiling techniques to assess potential causes. Use of multiple lines of evidence should also reduce the risk of false positives (Type I error or falsely concluding that there is a causal relationship when there is none) and false negatives (Type II error or falsely concluding there is not a causal relationship when there actually is). Understanding causal relationships and the mechanistic processes between environmental stressors and effects on biota is important in the effective management and restoration of impaired marine ecosystems.

Intergenerational cost–benefit analysis and marine ecosystem restoration

Ghoti papers Ghoti aims to serve as a forum for stimulating and pertinent ideas. Ghoti publishes succinct commentary and opinion that addresses important areas in fish and fisheries science. Ghoti contributions will be innovative and have a perspective that may lead to fresh and productive insight of concepts, issues and research agendas. All Ghoti contributions will be selected by the editors and peer reviewed. Etymology of Ghoti George Bernard Shaw (1856‐1950), polymath, playwright, Nobel prize winner, and the most prolific letter writer in history, was an advocate of English spelling reform. He was reportedly fond of pointing out its absurdities by proving that ‘fish’ could be spelt ‘ghoti’. That is: ‘gh’ as in ‘rough’, ‘o’ as in ‘women’ and ‘ti’ as in palatial.AbstractConventional cost–benefit analysis (CBA) tends to show that most ecosystem restoration programmes are not worthwhile in economic terms. This is because discounting puts more weight on current net benefits than future ones. I suggest that this is partly because conventional CBA is based on the current generation's time perspective (termed here the ‘discounting clock’). That is, net benefits are discounted starting when the analysis is carried out (the present). To tackle this problem, I propose the use of an intergenerational CBA, which takes into account the fact that current restoration efforts may produce benefits, in particular, fish protein, to future generations, and that these benefits need to be valued using the respective discounting clocks of the generation receiving them. This approach appears to meet the requirements imposed by most management jurisdictions, where there is an explicit or implied requirement to account for benefits to future generations in decision‐making concerning the use and management of marine resources.

Dynamic pollution control—time lags and optimal restoration of marine ecosystems

I apply a dynamic model—in linear–quadratic form—to the problem of eutrophication of coastal waters due to nitrogen pollution. The model includes two control measures, one upstream (agricultural abatement) and one downstream (mussel cultivation at the coast). In between, leachates are transported through groundwater and rivers. Groundwater is modelled as a complex system where pollution may decay, but may also be delayed for many years before reentering surface waters and flowing to the sea. Optimal pollution abatement measures are initially intense, declining as the steady state is approached. The decline is more marked for the downstream measure (mussel cultivation) than for agricultural abatement. This is in accordance with results from a simpler theoretical model. Where conditions allow it, mussel cultivation is an economically favourable complement to other forms of nitrogen abatement on the west coast of Sweden.

Restoration of temperate marine and coastal ecosystems: nudging nature

Restoration of temperate marine and coastal ecosystems: nudging nature

Restoration of temperate marine and coastal ecosystems: nudging nature

1. The main impacts on marine ecosystems are summarised and the potential for their restoration is discussed in relation to their key features. Rocky shores, seagrass beds and disused docks are focused on. 2. The term restoration is used to describe intervention in the recovery process of a marine ecosystem, with a view to enhancing the process, but not necessarily forcing the system to recover to its original condition. 3. Rocky shore systems are subject to shellfish and seaweed exploitation, point source pollution, diffuse impacts such as tributyl tin and acute impacts such as oil spills. The consideration of whether to employ restoration or allow natural recovery is discussed in relation to these systems. 4. Seagrass systems have suffered serious declines in many parts of the world due to the direct and indirect effects of human impacts. In the North Atlantic a wasting disease first noted in the 1930s caused a serious decline in the subtidal seagrass Zostera marina. The link between this disease and the marine slime mould Labrynthula zosterae is now well established. Human impacts on seagrass systems allow the disease to gain a foothold. Attempts at restoring seagrass beds have met with some success, but it is suggested that the action of conservation of remaining beds and better management of human activities may be the best approach. 5. Disused docks occur in many parts of Britain and Europe. Active management of the physical environment by mixing and biomanipulation by filter feeding organisms have led to improvements in water quality and ecosystem function. Thus healthy marine ecosystems have been restored to inner city areas, although these artificial marine lakes have few natural equivalents and are different from the original ecosystem at the site. 6. When compared to freshwater ecosystems, the scope for coastal and marine restoration is limited although the capacity for recovery is greater.