Browsing by Author "Neal, Benjamin"
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Item A contemporary baseline record of the world’s coral reefs(Scientific Data, 2020) Rodriguez-Ramirez, Alberto; González-Rivero, Manuel; Beijbom, Oscar; Bailhache, Christophe; Bongaerts, Pim; Brown, Kristen T.; Bryant, Dominic E. P.; Dalton, Peter; Dove, Sophie; Ganase, Anjani; Kennedy, Emma V.; Kim, Catherine J. S.; Lopez-Marcano, Sebastian; Neal, Benjamin; Radice, Veronica Z.; Vercelloni, Julie; Beyer, Hawthorne L.; Hoegh-Guldberg, OveAddressing the global decline of coral reefs requires effective actions from managers, policymakers and society as a whole. Coral reef scientists are therefore challenged with the task of providing prompt and relevant inputs for science-based decision-making. Here, we provide a baseline dataset, covering 1300 km of tropical coral reef habitats globally, and comprised of over one million geo-referenced, high-resolution photo-quadrats analysed using artificial intelligence to automatically estimate the proportional cover of benthic components. The dataset contains information on five major reef regions, and spans 2012–2018, including surveys before and after the 2016 global bleaching event. The taxonomic resolution attained by image analysis, as well as the spatially explicit nature of the images, allow for multi-scale spatial analyses, temporal assessments (decline and recovery), and serve for supporting image recognition developments. This standardised dataset across broad geographies offers a significant contribution towards a sound baseline for advancing our understanding of coral reef ecology and thereby taking collective and informed actions to mitigate catastrophic losses in coral reefs worldwide.Item Caribbean massive corals not recovering from repeated thermal stress events during 2005–2013(Ecology and Evolution, 2017) Neal, Benjamin; Khen, Adi; Treibitz, Tali; Beijbom, Oscar; O'Connor, Grace; Coffroth, Mary Alice; Knowlton, Nancy; Kriegman, David; Mitchell, B. Greg; Kline, David I.Massive coral bleaching events associated with high sea surface temperatures are forecast to become more frequent and severe in the future due to climate change. Monitoring colony recovery from bleaching disturbances over multiyear time frames is important for improving predictions of future coral community changes. However, there are currently few multiyear studies describing long-term outcomes for coral colonies following acute bleaching events. We recorded colony pigmentation and size for bleached and unbleached groups of co-located conspecifics of three major reef-building scleractinian corals (Orbicella franksi, Siderastrea siderea, and Stephanocoenia michelini; n = 198 total) in Bocas del Toro, Panama, during the major 2005 bleaching event and then monitored pigmentation status and changes live tissue colony size for 8 years (2005–2013). Corals that were bleached in 2005 demonstrated markedly different response trajectories compared to unbleached colony groups, with extensive live tissue loss for bleached corals of all species following bleaching, with mean live tissue losses per colony 9 months postbleaching of 26.2% (±5.4 SE) for O. franksi, 35.7% (±4.7 SE) for S. michelini, and 11.2% (±3.9 SE) for S. siderea. Two species, O. franksi and S. michelini, later recovered to net positive growth, which continued until a second thermal stress event in 2010. Following this event, all species again lost tissue, with previously unbleached colony species groups experiencing greater declines than conspecific sample groups, which were previously bleached, indicating a possible positive acclimative response. However, despite this beneficial effect for previously bleached corals, all groups experienced substantial net tissue loss between 2005 and 2013, indicating that many important Caribbean reef-building corals will likely suffer continued tissue loss and may be unable to maintain current benthic coverage when faced with future thermal stress forecast for the region, even with potential benefits from bleaching-related acclimation.Item Comparison of two photographic methodologies for collecting and analyzing the condition of coral reef ecosystems(Ecosphere, 2017) Bryant, D. E. P.; Rodriguez-Ramirez, A.; Phinn, S.; González-Rivero, M.; Brown, K. T.; Neal, Benjamin; Hoegh-Guldberg, O.; Dove, S.Coral reefs are declining rapidly in response to unprecedented rates of environmental change. Rapid and scalable measurements of how benthic ecosystems are responding to these changes are critically important. Recent technological developments associated with the XL Catlin Seaview Survey have begun to provide high-resolution 1-m2 photographic quadrats of 1.8–2 km of coral reefs at 10 m depth by using a semi-autonomous image collection SeaView II camera system (SVII). The rapid collection of images by SVII can result in images being taken at a variable distance (1–2 m) from the substrate as well as having natural light variability between images captured. This variability can affect the quality of taxonomic resolution archived from photographic quadrats captured by SVII. Conventional approaches for taking photographic quadrats of coral reefs involve taking images from a fixed distance with the use of artificial light. These methods often provide images that enable high taxonomic resolution, but are typically used to cover areas of 50–150 m. Here, we select key metrics associated with coral reef condition from a functional perspective to contrast how much is lost in terms of association and agreement from image annotations using SVII images (1-m2 photoquadrats) compared to conventional methods, capturing 0.5-m2 photoquadrats using a digital single lens reflex camera from a fixed height of 0.5 m above the benthos. Comparisons were made over the same 50-m linear transects at 15 sites in the Maldives. Photoquadrats were manually analyzed using an online image annotation tool and image repository called coral net with 25 randomly placed dots per 0.5 m2 of a quadrat. Our results reveal high levels of correlation and agreement between methods when measuring the abundance of hard corals as a functional group and individual labels, which make up hard corals as a functional group. These results demonstrate the two methods are comparable when measuring functional groups and coral communities on coral reefs. Therefore, involving rapid semi-automated technologies that maximize data collection for monitoring coral reefs does not necessarily imply that taxonomic resolution is compromised. This insight has important ramifications for detecting important changes in coral reef condition, such as a decline in coral cover or shifts in benthic community composition.Item Coral reef community changes in Karimunjawa National Park, Indonesia: Assessing the efficacy of management in the face of local and global stressors(Journal of Marine Science and Engineering, 2020) Kennedy, Emma V.; Vercelloni, Julie; Neal, Benjamin; Ambariyanto; Bryant, Dominic E. P.; Ganase, Anjani; Gartrell, Patrick; Brown, Kristen; Kim, Catherine J. S.; Hudatwi, Mu’alimah; Hadi, Abdul; Prabowo, Agus; Prihatinningsih, Puji; Haryanta, Sutris; Markey, Kathryn; Green, Susannah; Dalton, Peter; Lopez-Marcano, Sebastian; Rodriguez-Ramirez, Alberto; Gonzalez-Rivero, Manuel; Hoegh-Guldberg, OveKarimunjawa National Park is one of Indonesia’s oldest established marine parks. Coral reefs across the park are being impacted by fishing, tourism and declining water quality (local stressors), as well as climate change (global pressures). In this study, we apply a multivariate statistical model to detailed benthic ecological datasets collected across Karimunjawa’s coral reefs, to explore drivers of community change at the park level. Eighteen sites were surveyed in 2014 and 2018, before and after the 2016 global mass coral bleaching event. Analyses revealed that average coral cover declined slightly from 29.2 ± 0.12% (Standard Deviation, SD) to 26.3 ± 0.10% SD, with bleaching driving declines in most corals. Management zone was unrelated to coral decline, but shifts from massive morphologies toward more complex foliose and branching corals were apparent across all zones, reflecting a park-wide reduction in damaging fishing practises. A doubling of sponges and associated declines in massive corals could not be related to bleaching, suggesting another driver, likely declining water quality associated with tourism and mariculture. Further investigation of this potentially emerging threat is needed. Monitoring and management of water quality across Karimunjawa may be critical to improving resilience of reef communities to future coral bleaching.Item Fishers' local ecological knowledge reveals complex food web dynamics with rapidly warming waters(Fish and Fisheries) McClenachan, Loren; Neal, Benjamin; McMahan, Marissa; Batchelder, Ellie; Villanueva-Galarza, Neida; Grabowski, JonathanLocal ecological knowledge (LEK) can provide insight into ecosystem change, particularly in dynamic ecological conditions, such as those driven by climate change. In New England lobster fisheries, warming waters have the potential to disrupt food webs, as range-shifting species introduce novel ecological interactions. Here we use interviews with lobster fishers in Maine and Massachusetts to understand lobster fishers' LEK of dynamic food webs, taking a mental modelling approach to construct LEK food web models under rapidly warming waters. We find that fishers are observing a remarkable range of ecological interactions across habitats, collectively reporting knowledge of > 35 species that interact trophically with lobster across larval, juvenile, and adult life stages, ranging from terrestrial species like mink (Neovison vison) to deep sea species like redfish (Sebastes fasciatus). Our LEK food webs demonstrate perceptions of warming water altering species' abundances and interactions, with an overall negative impact on lobster fisheries. Fishers also report knowledge of complex interactions, including predation, competition, and habitat loss mediated by warming waters and changing species' abundances. Finally, we identify and categorise three main pathways that contribute to fishers' LEK, including observation, word of mouth, and inference. Our findings demonstrate that active fishers have complex understandings of food web interactions in dynamic ecosystems that are changing rapidly. With management unable to keep pace with climate-driven change, fishers' LEK is an invaluable source of knowledge, whose use could improve the ability to understand the diverse impacts of warming waters on coastal ecosystems.Item Fishing in turbulent waters: Resilience, risk, and trust in British Columbia’s declining commercial salmon fishery(FACETS, 2024) del Valle, Elias; Neal, Benjamin; Martínez-Candelas, Ilse; Dann, Patrick; Webb, Dawn; McClenachan, LorenThe impacts fishing communities face as a result of declining fisheries productivity and access may largely hinge on measurable attributes of their social resilience. Wild-origin Pacific salmon populations have been in a marked decline since the 1960s, resulting in progressively declining access for many commercial fisheries. More recent acute stressors have caused appreciable tribulation to commercial fishers in British Columbia, raising concern over their capacity to remain viable in the industry, and underscoring the need to examine the fishery under a social resilience framework. Here, we coupled an online survey instrument with in-depth interviews to assess commercial salmon fishers’ social resilience, socioeconomic characteristics, risk perceptions, trust in fishery management, and the relationships between these variables. Our results show that social resilience is low overall, with older, more experienced, and less diversified fishers being particularly vulnerable to declining salmon access. While 73% of fishers reported having plans to adapt to future declines in salmon access, 92% reported feeling that there are barriers impeding their adaptation, and 75% reported having no trust in fisheries management helping them adapt. Fishers’ social resilience was positively correlated with their trust in, and perceived trust from fisheries management.Item Forgotten whales, fading codfish: Perceptions of "natural" ecosystems inform visions of future recovery(People and Nature, 2023) McClenachan, Loren; Neal, Benjamin1. Perceptions of past ecological change affect views of current ecosystem state, but how do baselines help to shape stakeholders' visions of an idealized future? 2. Here, we investigate links between perceptions of natural baselines and visions for the nearshore Gulf of Maine among a key stakeholder group, active lobster fishers. We ask three related questions: (1) What do fishers perceive as a ‘natural’ Gulf of Maine? (2) How do perceptions of the past predict individual and collective visions of an ideal future? and (3) How is existing management perceived as supporting these visions? 3. We found that fishers perceived the ecosystem to be ‘natural’ an average of one decade before they started fishing. Three species dominated views of natural systems: cod Gadus morhua, lobster Homarus americanus, and herring Clupea harengus, but while long-time fishers associated abundant cod with a natural nearshore Gulf of Maine, memories of a historically cod-rich Gulf of Maine were fading among some younger fishers who began their careers after the cod crash in the 1990s. Perceptions of ‘natural’ ecosystems dictated future visions for the majority of taxa; on average, fishers remembered and desired abundant cod and herring, but perceived halibut Hippoglossus hippoglossus and endangered right whales Eubalaena glacialis to have always been rare. 4. Fishers described a vision for the future based on views of past ecological and social baselines, including fisheries deconsolidation and diversification, but expressed a lack of shared vision with and trust in federal management institutions to achieve these goals. In particular, memories of cod abundance in the 1970s and 1980s were coupled with memories of a diversified and accessible fishery, but fishers doubted that the recovery of cod would result in their restored access to cod fisheries. 5. Together our results demonstrate that past personal experiences limit perceptions of what is possible, highlighting both the value and limitations of local ecological knowledge in places that have experienced ecological change over centuries. They also demonstrate how stakeholder perceptions of both social and ecological baselines shape visions for future ecosystems but are mediated by contemporary issues like trust in institutions and fisheries access.Item Ghost reefs: Nautical charts document large spatial scale of coral reef loss over 240 years(Science Advances, 2017) McClenachan, Loren; O’Connor, Grace; Neal, Benjamin; Pandolfi, John M.; Jackson, Jeremy B. C.Massive declines in population abundances of marine animals have been documented over century-long time scales. However, analogous loss of spatial extent of habitat-forming organisms is less well known because georeferenced data are rare over long time scales, particularly in subtidal, tropical marine regions. We use high-resolution historical nautical charts to quantify changes to benthic structure over 240 years in the Florida Keys, finding an overall loss of 52% (SE, 6.4%) of the area of the seafloor occupied by corals. We find a strong spatial dimension to this decline; the spatial extent of coral in Florida Bay and nearshore declined by 87.5% (SE, 7.2%) and 68.8% (SE, 7.5%), respectively, whereas that of offshore areas of coral remained largely intact. These estimates add to finer-scale loss in live coral cover exceeding 90% in some locations in recent decades. The near-complete elimination of the spatial coverage of nearshore coral represents an underappreciated spatial component of the shifting baseline syndrome, with important lessons for other species and ecosystems. That is, modern surveys are typically designed to assess change only within the species’ known, extant range. For species ranging from corals to sea turtles, this approach may overlook spatial loss over longer time frames, resulting in both overly optimistic views of their current conservation status and underestimates of their restoration potential.Item Managing an invasive corallimorph at Palmyra Atoll National Wildlife Refuge, Line Islands, Central Pacific(Biological Invasions, 2018) Work, Thierry M.; Aeby, Greta S.; Neal, Benjamin; Price, Nichole N.; Conklin, Eric; Pollock, AmandaIn 2007, a phase shift from corals to corallimorpharians (CM) centered around a shipwreck was documented at Palmyra Atoll, Line Islands. Subsequent surveys revealed CM to be overgrowing the reef benthos, including corals and coralline algae, potentially placing coral ecosystems in the atoll at risk. This prompted the U.S. Fish and Wildlife Service, the lead management agency of the atoll, to remove the shipwreck. Subsequent surveys showed reductions in CM around the ship impact site. We explain patterns of spread of the CM in terms of both life history and local currents and show with a pilot study that pulverized bleach may be an effective tool to eradicate CM on a local scale. If applied strategically, particularly in heavily infested (> 66% cover) areas, active intervention such as this could be an effective management tool to reduce CM impact on localized areas and decrease colonization rate of remaining reefs. This is the first documentation of the response of an invasive cnidarian to shipwreck removal. While this was a singular event in Palmyra, the spatial and temporal patterns of this invasion and the eradications lessons described herein, are useful for anticipating and controlling similar situations elsewhere.Item Monitoring of coral reefs using artificial intelligence: A feasible and cost-effective approach(Remote Sensing, 2020) González-Rivero, Manuel; Beijbom, Oscar; Rodriguez-Ramirez, Alberto; Bryant, Dominic E. P.; Ganase, Anjani; Gonzalez-Marrero, Yeray; Herrera-Reveles, Ana; Kennedy, Emma V.; Kim, Catherine J. S.; Lopez-Marcano, Sebastian; Markey, Kathryn; Neal, Benjamin; Osborne, Kate; Reyes-Nivia, Catalina; Sampayo, Eugenia M.; Stolberg, Kristin; Taylor, Abbie; Vercelloni, Julie; Wyatt, Mathew; Hoegh-Guldberg, OveEcosystem monitoring is central to effective management, where rapid reporting is essential to provide timely advice. While digital imagery has greatly improved the speed of underwater data collection for monitoring benthic communities, image analysis remains a bottleneck in reporting observations. In recent years, a rapid evolution of artificial intelligence in image recognition has been evident in its broad applications in modern society, offering new opportunities for increasing the capabilities of coral reef monitoring. Here, we evaluated the performance of Deep Learning Convolutional Neural Networks for automated image analysis, using a global coral reef monitoring dataset. The study demonstrates the advantages of automated image analysis for coral reef monitoring in terms of error and repeatability of benthic abundance estimations, as well as cost and benefit. We found unbiased and high agreement between expert and automated observations (97%). Repeated surveys and comparisons against existing monitoring programs also show that automated estimation of benthic composition is equally robust in detecting change and ensuring the continuity of existing monitoring data. Using this automated approach, data analysis and reporting can be accelerated by at least 200x and at a fraction of the cost (1%). Combining commonly used underwater imagery in monitoring with automated image annotation can dramatically improve how we measure and monitor coral reefs worldwide, particularly in terms of allocating limited resources, rapid reporting and data integration within and across management areas.Item Possible control of acute outbreaks of a marine fungal pathogen by nominally herbivorous tropical reef fish(Oecologia, 2020) Neal, Benjamin; Honisch, B.; Warrender, T.; Williams, G. J.; Work, T. M.; Price, N. N.Primary producers in terrestrial and marine systems can be affected by fungal pathogens threatening the provision of critical ecosystem services. Crustose coralline algae (CCA) are ecologically important members of tropical reef systems and are impacted by coralline fungal disease (CFD) which manifests as overgrowth of the CCA crust by fungal lesions causing partial to complete mortality of the CCA host. No natural controls for CFD have been identified, but nominally herbivorous fish could play a role by consuming pathogenic fungi. We documented preferential grazing on fungal lesions by adults of six common reef-dwelling species of herbivorous Acanthuridae and Labridae, (surgeonfish and parrotfish) which collectively demonstrated an ~ 80-fold higher grazing rate on fungal lesions relative to their proportionate benthic coverage, and a preference for lesions over other palatable substrata (e.g. live scleractinian coral, CCA, or algae). Furthermore, we recorded a ~ 600% increase in live CFD lesion size over an approximately 2-week period when grazing by herbivorous fish was experimentally excluded suggesting that herbivorous reef fish could control CFD progression by directly reducing biomass of the fungal pathogen. Removal rates may be sufficient to allow CCA to recover from infection and explain historically observed natural waning behaviour after an outbreak. Thus, in addition to their well-known role as determinants of macroalgal overgrowth of reefs, herbivorous fish could thus also be important in control of diseases affecting crustose coralline algae that stabilize the foundation of coral reef substrata.