37 research outputs found
Predicting Optimal Sites for Ecosystem Restoration Using Stacked-Species Distribution Modeling
Habitat restoration is an important tool for managing degraded ecosystems, yet the success of restoration projects depends in part on adequately identifying preferred sites for restoration. Species distribution modeling using a machine learning approach provides novel tools for mapping areas of interest for restoration projects. Here we use stacked-species distribution models (s-SDMs) to identify candidate locations for installment of manmade reefs, a useful management tool for restoring structural habitat complexity and the associated biota in marine ecosystems. We created species distribution models for 21 species of commercial, recreational, ecological, or conservation importance within the Southern California Bight based on observations from long-term reef surveys combined with high resolution (200 m × 200 m) geospatial environmental data layers. We then combined the individual species models to create a stacked-species habitat suitability map, identifying over 800 km2 of potential area for reef restoration within the Bight. When considering only the 21 focal species, s-SDM scores were positively associated with observed bootstrap species richness not only on natural reefs (linear model: slope = 0.27, 95% CI = 0.17–0.36, w = 1), but also this result was supported by two independent test datasets. The predicted richness from this linear model was associated with observed species richness when considering only the focal species on manmade reefs (linear model: slope = 0.52, 95% CI = 0.13–0.92, w = 1) and also when considering 204 other non-focal species on both natural and manmade reefs in southern California (slope = 3.65, 95% CI = 2.93–4.37, w = 1). Finally, our results demonstrate that the existing manmade reefs included in our study on average are located in regions with habitat suitability that is not only less suitable than natural reefs (t-value = –5.4; p < 0.05), but also only slightly significantly better than random (p < 0.05), demonstrating a need for more biologically informed placement of manmade reefs. The stacked-species distribution model provides insight for marine restoration projects in southern California specifically, but more generally this method can also be widely applied to other types of habitat restoration including both marine and terrestrial
Where the Weird Things Are: A Collection of Species Range Extensions in the Southern California Bight
A large-scale monitoring program associated with the establishment of a marine protected area network in southern California provided an opportunity to observe and document unique or rare species across the region. Scientists and students from several educational and research institutions surveyed 145 subtidal reefs, 39 intertidal reefs, and five sandy beaches from 2011-2017, a period of time where oceanographic and climatic conditions changed serially and dramatically. In conjunction with an increase in monitoring frequency and locations, dramatic shifts in oceanographic climate during this same time period likely caused shifts in tolerable habitat conditions for many nearshore species. Here we describe range extensions – both to the north and south – of fourteen marine fish, invertebrate, and algae species as observed during the 2011-2012 South Coast MPA Baseline Program and subsequent monitoring efforts
To what extent can decommissioning options for marine artificial structures move us toward environmental targets?
Switching from fossil fuels to renewable energy is key to international energy transition efforts and the move toward net zero. For many nations, this requires decommissioning of hundreds of oil and gas infrastructure in the marine environment. Current international, regional and national legislation largely dictates that structures must be completely removed at end-of-life although, increasingly, alternative decommissioning options are being promoted and implemented. Yet, a paucity of real-world case studies describing the impacts of decommissioning on the environment make decision-making with respect to which option(s) might be optimal for meeting international and regional strategic environmental targets challenging. To address this gap, we draw together international expertise and judgment from marine environmental scientists on marine artificial structures as an alternative source of evidence that explores how different decommissioning options might ameliorate pressures that drive environmental status toward (or away) from environmental objectives. Synthesis reveals that for 37 United Nations and Oslo-Paris Commissions (OSPAR) global and regional environmental targets, experts consider repurposing or abandoning individual structures, or abandoning multiple structures across a region, as the options that would most strongly contribute toward targets. This collective view suggests complete removal may not be best for the environment or society. However, different decommissioning options act in different ways and make variable contributions toward environmental targets, such that policy makers and managers would likely need to prioritise some targets over others considering political, social, economic, and ecological contexts. Current policy may not result in optimal outcomes for the environment or society
Developing expert scientific consensus on the environmental and societal effects of marine artificial structures prior to decommissioning
This work was supported by the UK Natural Environment Research Council and the INSITE programme [INSITE SYNTHESIS project, grant number NE/W009889/1].Thousands of artificial (‘human-made’) structures are present in the marine environment, many at or approaching end-of-life and requiring urgent decisions regarding their decommissioning. No consensus has been reached on which decommissioning option(s) result in optimal environmental and societal outcomes, in part, owing to a paucity of evidence from real-world decommissioning case studies. To address this significant challenge, we asked a worldwide panel of scientists to provide their expert opinion. They were asked to identify and characterise the ecosystem effects of artificial structures in the sea, their causes and consequences, and to identify which, if any, should be retained following decommissioning. Experts considered that most of the pressures driving ecological and societal effects from marine artificial structures (MAS) were of medium severity, occur frequently, and are dependent on spatial scale with local-scale effects of greater magnitude than regional effects. The duration of many effects following decommissioning were considered to be relatively short, in the order of days. Overall, environmental effects of structures were considered marginally undesirable, while societal effects marginally desirable. Experts therefore indicated that any decision to leave MAS in place at end-of-life to be more beneficial to society than the natural environment. However, some individual environmental effects were considered desirable and worthy of retention, especially in certain geographic locations, where structures can support improved trophic linkages, increases in tourism, habitat provision, and population size, and provide stability in population dynamics. The expert analysis consensus that the effects of MAS are both negative and positive for the environment and society, gives no strong support for policy change whether removal or retention is favoured until further empirical evidence is available to justify change to the status quo. The combination of desirable and undesirable effects associated with MAS present a significant challenge for policy- and decision-makers in their justification to implement decommissioning options. Decisions may need to be decided on a case-by-case basis accounting for the trade-off in costs and benefits at a local level.Publisher PDFPeer reviewe
Developing expert scientific consensus on the environmental and societal effects of marine artificial structures prior to decommissioning
Thousands of artificial (‘human-made’) structures are present in the marine environment, many at or approaching end-of-life and requiring urgent decisions regarding their decommissioning. No consensus has been reached on which decommissioning option(s) result in optimal environmental and societal outcomes, in part, owing to a paucity of evidence from real-world decommissioning case studies. To address this significant challenge, we asked a worldwide panel of scientists to provide their expert opinion. They were asked to identify and characterise the ecosystem effects of artificial structures in the sea, their causes and consequences, and to identify which, if any, should be retained following decommissioning. Experts considered that most of the pressures driving ecological and societal effects from marine artificial structures (MAS) were of medium severity, occur frequently, and are dependent on spatial scale with local-scale effects of greater magnitude than regional effects. The duration of many effects following decommissioning were considered to be relatively short, in the order of days. Overall, environmental effects of structures were considered marginally undesirable, while societal effects marginally desirable. Experts therefore indicated that any decision to leave MAS in place at end-of-life to be more beneficial to society than the natural environment. However, some individual environmental effects were considered desirable and worthy of retention, especially in certain geographic locations, where structures can support improved trophic linkages, increases in tourism, habitat provision, and population size, and provide stability in population dynamics. The expert analysis consensus that the effects of MAS are both negative and positive for the environment and society, gives no strong support for policy change whether removal or retention is favoured until further empirical evidence is available to justify change to the status quo. The combination of desirable and undesirable effects associated with MAS present a significant challenge for policy- and decision-makers in their justification to implement decommissioning options. Decisions may need to be decided on a case-by-case basis accounting for the trade-off in costs and benefits at a local level
Influence of offshore oil and gas structures on seascape ecological connectivity.
Offshore platforms, subsea pipelines, wells and related fixed structures supporting the oil and gas (O&G) industry are prevalent in oceans across the globe, with many approaching the end of their operational life and requiring decommissioning. Although structures can possess high ecological diversity and productivity, information on how they interact with broader ecological processes remains unclear. Here, we review the current state of knowledge on the role of O&G infrastructure in maintaining, altering or enhancing ecological connectivity with natural marine habitats. There is a paucity of studies on the subject with only 33 papers specifically targeting connectivity and O&G structures, although other studies provide important related information. Evidence for O&G structures facilitating vertical and horizontal seascape connectivity exists for larvae and mobile adult invertebrates, fish and megafauna; including threatened and commercially important species. The degree to which these structures represent a beneficial or detrimental net impact remains unclear, is complex and ultimately needs more research to determine the extent to which natural connectivity networks are conserved, enhanced or disrupted. We discuss the potential impacts of different decommissioning approaches on seascape connectivity and identify, through expert elicitation, critical knowledge gaps that, if addressed, may further inform decision making for the life cycle of O&G infrastructure, with relevance for other industries (e.g. renewables). The most highly ranked critical knowledge gap was a need to understand how O&G structures modify and influence the movement patterns of mobile species and dispersal stages of sessile marine species. Understanding how different decommissioning options affect species survival and movement was also highly ranked, as was understanding the extent to which O&G structures contribute to extending species distributions by providing rest stops, foraging habitat, and stepping stones. These questions could be addressed with further dedicated studies of animal movement in relation to structures using telemetry, molecular techniques and movement models. Our review and these priority questions provide a roadmap for advancing research needed to support evidence-based decision making for decommissioning O&G infrastructure
Platform Survey Database
<p>Between 1995 and 2011, Dr. Milton Love and colleagues surveyed the fish assemblages of 22 oil and gas platforms off southern California using the manned research submersibles Delta and Dual DeepWorker. This work was funded by the United States Bureau of Ocean Energy Management (previously the Minerals Management Service), the Biological Resources Division of the United States Geological Survey, and the California Artificial Reef Enhancement Program. The data from these surveys was entered into a Microsoft Access database called Rigbase.</p>
<p>Please cite as: Â Love, Milton (2013): Platform Survey Database. figshare. http://dx.doi.org/10.6084/m9.figshare.1501507</p>
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<p>For an explanation of the data tables see the pdf at the link below:</p>
<p>http://lovelab.id.ucsb.edu/rigbase_2003/rigbase_database_documentation.pdf</p>
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<p>For more details on the research please see the Love Lab website:</p>
<p>http://www.lovelab.id.ucsb.edu/platform_databse.html</p>
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<p>Database Changelog:</p>
<p>08-20-2013:Â All tables have been altered.Minor corrections have been made to tables:</p>
<p>Tbl_TRANSECT</p>
<p>Tbl_FISH</p>
<p>Tbl_HABITAT</p>
<p>Navigation data have been corrected for tbl_DIVE so that latitude and longitude reflect the starting point of the first transect, except for oil platform dives when they are the centerpoint of the platform.</p>
<p>Two new tables have been added with detailed navigation points.</p>
<p>Tbl_Nav_1995to2001 contains navigation fixes at 5 minute intervals along a transect.</p>
<p>Tbl_Nav_2002to2011 contains navigation fixes every few seconds along a transect.</p>
<p>Tbl_Depth has been replaced with tbl_CTD which contains additional information (e.g.salinity) for dives later than 2001.</p>
<p>03-05-2012: Data made available to public.</p>
<p>08-24-2012: "Temperature" data added to tbl_Fish for year=2011; "Depth" corrected in tbl_Fish for dive 7244</p>
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Using GIS Mapping of the Extent of Nearshore Rocky Reefs to Estimate the Abundance and Reproductive Output of Important Fishery Species
Kelp Bass (Paralabrax clathratus) and California Sheephead (Semicossyphus pulcher) are economically and ecologically valuable rocky reef fishes in southern California, making them likely indicator species for evaluating resource management actions. Multiple spatial datasets, aerial and satellite photography, underwater observations and expert judgment were used to produce a comprehensive map of nearshore natural rocky reef habitat for the Santa Monica Bay region (California, USA). It was then used to examine the relative contribution of individual reefs to a regional estimate of abundance and reproductive potential of the focal species. For the reefs surveyed for fishes (i.e. 18 out of the 22 in the region, comprising 82 % the natural rocky reef habitat,30 m depth, with a total area of 1850 ha), total abundance and annual egg productio
DataSheet_1_Habitat type and environmental conditions influence the age and growth of a temperate marine damselfish.docx
Life history parameters for fishes have generally been applied to species across their entire range, however, different ecological and environmental conditions and processes (e.g., sea surface temperature, habitat, primary productivity, fishing mortality, resource availability) influence life history patterns at smaller spatial scales. By focusing on a historically protected species, we determined how environmental and ecological factors shape patterns in growth and longevity, without the impact of fishing. The Garibaldi (Hypsypops rubicundus) is a territorial marine damselfish native to the shallow rocky reefs of southern California. Garibaldi were collected from five mainland locations and five Channel Islands throughout the Southern California Bight. Paired natural reef and artificial reef habitats (i.e., breakwaters and jetties) in each mainland location were sampled. Otolith-based ageing and biological data from these populations were used to assess how age and growth vary by location, reef type (natural/artificial), island or mainland, mean annual sea surface temperature, and/or sex. The annual formation of growth increments in otoliths was validated in-situ using tetracycline mark-recapture methods to confirm that increments are formed annually. Garibaldi grew significantly larger on artificial reefs than on natural reefs but tended to live longer on paired natural reefs. Regionally, growth and longevity followed mean annual sea surface temperature gradients, consistent with Bergmann’s rule. Garibaldi exhibited clear sexual size dimorphism; males grew larger, which is uncharacteristic for both damselfish and other marine fishes from the southern California. The Garibaldi collected for this study had a maximum age of 57 years, which makes this the longest lived damselfish species by two decades.</p