Pilot studies have indicated that peroral endoscopic myotomy (POEM) might be a safe and effective treatment for achalasia. We performed a prospective, international, multicenter study to determine ...the outcomes of 70 patients who underwent POEM at 5 centers in Europe and North America. Three months after POEM, 97% of patients were in symptom remission (95% confidence interval, 89%–99%); symptom scores were reduced from 7 to 1 ( P < .001) and lower esophageal sphincter pressures were reduced from 28 to 9 mm Hg ( P < .001). The percentage of patients in symptom remission at 6 and 12 months was 89% and 82%, respectively. POEM was found to be an effective treatment for achalasia after a mean follow-up period of 10 months. Clinical Trials Gov Registration number: NCT01405417.
Abstract
Spatial management has been adopted worldwide to mitigate habitat impacts while achieving fisheries management objectives. However, there is little theory or practice for predicting the ...impact of spatial regulations on future fishery production; this would provide scientific basis for greater flexibility in fisheries management when balancing fishery and conservation goals. We propose that predicting changes in fishery production resulting from human activities within specific habitats is a “Grand Challenge” for habitat science in the coming decade(s). We then outline three difficulties in resolving this Grand Habitat Challenge, including: (i) stage-structured responses to habitat impacts, (ii) nonlocal responses, and (iii) mechanistic associations among habitat variables. We next discuss analytical approaches to address each difficulty, respectively: (i) ongoing developments for spatial demographic models; (ii) individual movement models and rank-reduction approaches to identify regional variability; (iii) causal analysis involving structural equation models. We demonstrate nonlocal effects in detail using a diffusion-taxis movement model applied to sablefish (Anoplopoma fimbria) in the Gulf of Alaska and discuss all three approaches for deep-sea corals. Despite isolated progress to resolve individual difficulties, we argue that resolving this Grand Habitat Challenge will require a coordinated commitment from science agencies worldwide.
Trait‐based climate vulnerability assessments based on expert evaluation have emerged as a rapid tool to assess biological vulnerability when detailed correlative or mechanistic studies are not ...feasible. Trait‐based assessments typically view vulnerability as a combination of sensitivity and exposure to climate change. However, in some locations, a substantial amount of information may exist on system productivity and environmental conditions (both current and projected), with potential disparities in the information available for data‐rich and data‐poor stocks. Incorporating this level of detailed information poses challenges when conducting, and communicating uncertainty from, rapid vulnerability assessments. We applied a trait‐based vulnerability assessment to 36 fish and invertebrate stocks in the eastern Bering Sea (EBS), a data‐rich ecosystem. In recent years, the living marine resources of the EBS and Aleutian Islands have supported fisheries worth more than US $1 billion of annual ex‐vessel value. Our vulnerability assessment uses projections (to 2039) from three downscaled climate models, and graphically characterizes the variation in climate projections between climate models and between seasons. Bootstrapping was used to characterize uncertainty in specific biological traits and environmental variables, and in the scores for sensitivity, exposure, and vulnerability. The sensitivity of EBS stocks to climate change ranged from “low” to “high,” but vulnerability ranged between “low” and “moderate” due to limited exposure to climate change. Comparison with more detailed studies reveals that water temperature is an important variable for projecting climate impacts on stocks such as walleye pollock (Gadus chalcogrammus), and sensitivity analyses revealed that modifying the rule for determining vulnerability increased the vulnerability scores. This study demonstrates the importance of considering several uncertainties (e.g., climate projections, biological, and model structure) when conducting climate vulnerability assessments, and can be extended in future research to consider the vulnerability of user groups dependent on these stocks.
We conducted a trait‐based climate vulnerability assessment for groundfish, salmon, and crab stocks in the eastern Bering Sea, a data‐rich region, and leveraged existing downscaled climate projections, species distribution models, and (for some stocks) detailed biological studies. The vulnerability ranged from “low” to “moderate”; however, comparison with more detailed studies indicates that water temperature may have important effects on climate vulnerability for some stocks. We also demonstrate how several types of uncertainties (climate projections, biological, and model structure) can be analyzed and communicated, including bootstrapping of the results.
...in 2013, an area of water in the northeast Pacific Ocean more than three times the size of Texas, known as The Blob, warmed by nearly 3°C. Over 18 months, these warm waters spread across the ...entire west coast of North America, from the Gulf of Alaska to the tip of the Baja Peninsula in Mexico. Coastal communities need to understand what is unfolding if they are to adapt. Because the precise meaning remains unclear, miscommunication and misunderstanding are rife. Here we - the members of the US National Oceanic and Atmospheric Administration (NOAA) Marine Ecosystem Task Force - propose how to define basic terms to clarify what kinds of ocean warming the world has in store. Ocean surface waters have warmed at an average rate of 0.06 °C per decade since pre-industrial times, compared with 0.1 °C per decade for surface air temperature over land; both rates are rising3.
Abstract
Crab populations in the eastern Bering Sea support some of the most valuable fisheries in the United States, but their future productivity and distribution are uncertain. We explore observed ...changes in the productivity and distribution for snow crab, Tanner crab, and Bristol Bay red king crab. We link historical indices of environmental variation and predator biomass with observed time series of centroids of abundance and extent of crab stock distribution; we also fit stock–recruit curves including environmental indices for each stock. We then project these relationships under forcing from global climate models to forecast potential productivity and distribution scenarios. Our results suggest that the productivity of snow crab is negatively related to the Arctic Oscillation (AO) and positively related to ice cover; Tanner crab’s productivity and distribution are negatively associated with cod biomass and sea surface temperature. Aspects of red king crab distribution and productivity appear to be related to bottom temperature, ice cover, the AO, and/or cod biomass. Projecting these relationships forward with available forecasts suggests that Tanner crab may become more productive and shift further offshore, red king crab distribution may contract and move north, and productivity may decrease for snow crab as the population contracts northward.
Abstract
Climate-related distribution shifts for marine species are, in general, amplified in northern latitudes. The objective of this study was to predict future distributions of commercially ...important species in the eastern Bering Sea under six climate scenarios, by incorporating predictions of future oceanographic conditions. We used species distribution modelling to determine potential distribution changes in four time periods (2013–2017, 2030–2039, 2060–2069, and 2090-2099) relative to 1982–2012 for 16 marine fish and invertebrates. Most species were predicted to have significant shifts in the centre of gravity of the predicted abundance, the area occupied, and the proportion of the predicted abundance found in the standard bottom trawl survey area. On average the shifts were modest, averaging 35.2 km (ranging from 1 to 202 km). There were significant differences in the predicted trend for distribution metrics among climate scenarios, with the most extensive changes in distribution resulting from Representative Concentration Pathway 8.5 climate scenarios. The variability in distributional shifts among years and climate scenarios was high, although the magnitudes were low. This study provides a basis for understanding where fish populations might expand or contract in future years. This will provide managers’ information that can help guide appropriate actions under warming conditions.
Recruitment variability is poorly understood for Bering Sea crab stocks. The nearshore area in southwest Bristol Bay (Alaska, USA) is hypothesized as having historically (i.e., prior to ~ 1980) been ...the most important spawning ground for Bristol Bay red king crab (Paralithodes camtschaticus) because post‐larvae are thought to have been most likely to reach optimal settlement habitat along the Alaska Peninsula when hatched from this area as part of an endless‐belt reproductive strategy. We coupled a biophysical and oceanographic circulation model to test this hypothesis, investigate larval connectivity of more recent female spatial distributions, and evaluate the importance of climate variability on larval advection trajectories. Predicted settlement success varied through changes in larval pelagic duration and oceanographic circulation patterns: Shorter advective distance was associated with warmer conditions, causing higher rates of local retention relative to cold conditions. Contrary to earlier models, most larvae hatched in southwest Bristol Bay were advected offshore away from good habitat, whereas larvae hatched in central and nearshore Bristol Bay were retained in or advected to good habitat along the Alaska Peninsula. Our results suggest contemporary spatial distributions can supply settlement‐competent larvae to nurseries along the Alaska Peninsula and that under certain conditions, larvae may reach the Pribilof Islands when hatched from southwest Bristol Bay. Our study informs the role of environmental variability on larval transport and provides context within which to structure future investigations of recruitment mechanisms.
Climate change may impact ocean ecosystems through a number of mechanisms, including shifts in primary productivity or plankton community structure, ocean acidification, and deoxygenation. These ...processes can be simulated with global Earth system models (ESMs), which are increasingly being used in the context of fisheries management and other living marine resource (LMR) applications. However, projections of LMR-relevant metrics such as net primary production can vary widely between ESMs, even under identical climate scenarios. Therefore, the use of ESM should be accompanied by an understanding of the structural differences in the biogeochemical sub-models within ESMs that may give rise to these differences. This review article provides a brief overview of some of the most prominent differences among the most recent generation of ESM and how they are relevant to LMR application.
The high-latitude Pacific is home to highly productive ecosystems, including vast populations of commercially and subsistence harvested fish. These regions can be challenging to sample directly. Over ...several decades at the NOAA Pacific Marine Environmental Laboratory, we have applied numerical models to infer past, present, and future states of these regional oceans and their biota. These estimates are provided to fisheries scientists to help identify the local biophysical dynamics that underlie marine resource fluctuations and to managers to help develop effective management strategies in the face of short– and long-term environmental changes.
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