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

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

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

Relationship between length and annual egg production for California Sheephead and Kelp Bass.

<p>Relationship between total length and annual egg production for individual California Sheephead (<i>Semicossyphus pulcher</i>) (solid line) and Kelp Bass (<i>Paralabrax clathratus</i>) (dashed line) calculated using sources in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030290#pone-0030290-t002" target="_blank">Table 2</a>.</p

California Sheephead size structure at Little Dume and Rocky Point.

<p>California Sheephead (<i>Semicossyphus pulcher</i>) size structure (proportion of individuals per 5 cm size class) of females (white) and males (black) for Little Dume reef and Rocky Point reef. The legal minimum size limit (30 cm) for recreational fisheries is indicated by a black line.</p

Habitat layers at Ridges and Rocky Point reefs.

<p>Habitat layers at Ridges and Rocky Point reefs using kml file displayed with Google Earth™. (A) Orange – side scan sonar - Habitat Classification. (B) Green – Kelp Canopy. (C) Yellow – course scale habitat and previously unmapped shallow rocky reef habitat. (D) All three layers combined exhibiting total extent of rocky reef habitat which is displayed for the region in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030290#pone-0030290-g001" target="_blank">Figure 1</a>.</p

Extent of nearshore rocky reefs in Santa Monica Bay, California.

<p>Extent of nearshore rocky reefs in Santa Monica Bay, California for (A) western Malibu, (B) eastern Malibu and (C) Palos Verdes Peninsula. The 30 m depth contour appears as a dotted line. Note that while some artificial reefs (for example sewer outfalls at Whites Point) and natural rock reef habitat extending below 30m are included here, they were not included in the area estimates (total extent of rocky reef habitat <30 m depth) in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030290#pone-0030290-t001" target="_blank">Table 1</a>.</p