Serafy JE, GS Shideler, RJ Araújo, and I Nagelkerken

Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several species known to have different habitats as juveniles and adults. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. Authors of this paper used the REEF database to evaluate mangrove-reef connectivity at the Caribbean regional scale. They specifically asked: (1) Are reef fish abundances limited by mangrove forest area?; and (2) Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? They tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as “mangrove-dependent”. Results showed that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. This is the first scientific study to show that at a large regional scale (i.e., the Wider Caribbean), greater mangrove forest size generally functions to increase the densities on neighboring reefs of those fishes that use these shallow, vegetated habitats as nurseries.

This study is a great example of the power and impact that long-term, wide-spread citizen science programs such as the REEF Volunteer Fish Survey Project can have on addressing important ecological and management questions that would otherwise be near impossible to evaluate.

PLoS ONE
10(11): e0142022
2015
Thorson, JT, MD Scheuerell, BX Semmens, and CV Pattengill-Semmens
Managing natural populations and communities requires detailed information regarding demographic processes (or status of a population) at large spatial and temporal scales. This combination is challenging for both traditional scientific surveys, which often operate at localized scales, and citizen science designs, which often provide data with few auxiliary information (i.e. no information about individual age or condition). The authors of this study combine citizen science data collected at large scales (REEF Volunteer Fish Survey Project data) with recently developed statistical demographic modeling techniques. The model analysis included two managed reef fishes in the Gulf of Mexico to estimate demographic trends, habitat associations, and interannual variability in recruitment of Goliath Grouper and Mutton Snapper. The results identify strong preferences for artificial structure for the recovering Goliath Grouper, while revealing little evidence of either habitat associations or trends in abundance for Mutton Snapper. Results are also contrasted with a typical modeling approach to demonstrate the importance of accounting for the statistical complexities implied by spatially structured citizen science data. Results also highlight the utility and management benefits of combining demographic models and citizen science data.
Ecology
dx.doi.org/10.1890/13-2223.1
2014
Lotterhos, KE, SJ Dick, and DR Haggarty

REEF data were used to validate population estimates of Black Rockfish throughout western Canada, Washington State, and Oregon. These results were then used to evaluate the efficacy of marine reserve networks in these areas. The authors of the study estimated the scale of dispersal from genetic data in the black rockfish, and compared this estimate with the distance between Rockfish Conservation Areas that aim to protect this species (essentially evaluating whether the reserves are "connected" enough). Their findings showed that within each country, the distance between conservation areas was generally well connected. The distance between the networks in the two countries, however, was greater than the average dispersal per rockfish generation.

Evolutionary Applications
(2014) 238–259
2014
Archer, SK, JE Allgeier, BX Semmens, SA Heppell, CV Pattengill-Semmens, AD Rosemond, PG Bush, CM McCoy, BC Johnson, CA Layman

This paper presents results from a study conducted as part of REEF's Grouper Moon Project, evaluating the potential ecosystem-level effect of Nassau Grouper aggregations. In particular, the study looked at the impact the spawning aggregation has in creating biogeochemical "hot moments", which occur when a temporary increase in availability of one or more limiting nutrients results in elevated rates of biogeochemical reactions. In this case, the limited nutrients are nitrogen and phosphorus, and the temporary increase is resulting from all of the grouper excrement that results when approximately 5,000 Nassau Grouper gather in a small area for 10 days during the spawning season.

Coral Reefs
10.1007/s00338-014-1208-4
2014
Akins, JL, JA Morris Jr, and SJ Green

Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible.

Ecology and Evolution
10.1002/ece3.1171
2014
Green, S.J., N.K. Dulvy, A.L. M. Brooks, J.L. Akins, A.B. Cooper, S. Miller, and I.M. Côté

The study, conducted by Dr. Stephanie Green (OSU/REEF), Lad Akins (REEF), and others, confirms for the first time that controlling lionfish populations in the western Atlantic Ocean can pave the way for a recovery of native fish. Even if it's one speared fish at a time, data are showing that removals can be effective. And not every lionfish need be removed…the research findings document that reducing lionfish numbers by specified amounts will allow a rapid recovery of native fish biomass. Over 18 months, the biomass of native prey fishes increased an average 50-70% on reefs where lionfish numbers were suppressed below target levels predicted to cause prey depletion. On reefs where lionfish numbers remained higher than target levels, the biomass of prey fishes decreased by a further 50%. While complete eradication of lionfish from the Caribbean is not likely, groups are actively removing them from coastal areas (mostly via spear and net). This study is a first step in showing that strategic local efforts that suppress the invasion to low levels can help protect and recover native fish communities affected by lionfish. This ground-breaking invasive lionfish research was conducted as a collaboration between REEF, Oregon State University, Simon Fraser University, and the Cape Eleuthera Institute.

Ecological Applications
24: 1311–1322
2014
Jackson, AM, BX Semmens, Y Sadovy de Mitcheson, RS Nemeth, SA Heppell, PG Bush, A Aguilar-Perera, JAB Claydon, MC Calosso, KS Sealey, MT Schärer, G Bernardi
This study, co-authored by scientists from REEF's Grouper Moon Project, evaluated genetic connectedness between Nassau Grouper populations throughout the Caribbean. The authors obtained genetic tissue samples from 620 Nassau Grouper from 19 sites across 9 countries, including the Cayman Islands. They found evidence for strong genetic differentiation among Nassau Grouper subpopulations throughout the Caribbean. These results suggest that, despite a lack of physical barriers, Nassau grouper form multiple distinct subpopulations in the Caribbean Sea. Oceanography (regional currents, eddies) likely plays an important role in retaining larvae close to spawning sites at both local and regional spatial scales. These findings highlight the importance of conservation initiatives such at REEF's Grouper Moon program in the Cayman Islands.
PLoS ONE
DOI: 10.1371/journal.pone.0097508
2014
Côté​, IM, L Akins, E Underwood, J Curtis-Quick, SJ Green
Frequent culling of the invasive Indo-Pacific Lionfish throughout the Caribbean has been shown to cause a shift towards more wary and reclusive behaviour by lionfish, which has prompted calls for halting culls. This paper, co-authored by REEF Lionfish Program researchers, addresses those concerns and reviews research conducted by REEF and other research efforts. Culling successfully lowers lionfish numbers and has been shown to stabilise or even reverse declines in native prey fish. Partial culling is often as effective as complete local eradication, yet requires significantly less time and effort. Abandoning culling altogether would therefore be seriously misguided and a hindrance to conservation. The authors also offer suggestions for how to design removal programs that minimize behavioural changes and maximize culling success.
PeerJ PrePrints
2:e398v1
2014
Scyphers, SB, SP Powers, JL Akins, JM Drymon, CW Martin, ZH Schobernd, PJ Schofield, RL Shipp, and TS Switzer

The authors of this study (including REEF staff Lad Akins) examined the recent case of Indo-Pacific lionfish invading Northern Gulf of Mexico coastal waters. The authors compared traditional reef fish monitoring efforts to less traditional data including the observations of divers through REEF's Volunteer Fish Survey Project and spearfishers. They found that citizen observations documented lionfish 1-2 years earlier and more frequently than the more traditional monitoring efforts. The authors also explored the willingness of spearfishers to help minimize impacts of the invasion by harvesting lionfish. They found that spearfishers who had encountered more lionfish while diving perceived them as more harmful to the habitat than less experienced divers and were also more likely to participate in harvesting initiatives. The authors also report that encouragement from scientists and managers was a far better motivator than the desire to harvest lionfish for personal consumption. This study demonstrates the value of engaging citizens for assessing and responding to large-scale and time-sensitive conservation problems.

Conservation Letters
doi: 10.1111/conl.12127
2014
Francisco-Ramos V, Arias-González JE

There is an increasing need to examine regional patterns of diversity in coral-reef systems because their biodiversity is declining globally. The authors used REEF data from 80 sites from 6 eco-regions throughout the Caribbean to evaluate patterns of biodiversity. Specifically, they used "additive partitioning", which quantifies the contribution of different types of diversity (alpha and beta; comparing diversity between sites within a region and between regions) to total diversity across different spatial scales. The primary objective was to identify patterns of reef-fish diversity across multiple spatial scales under different scenarios, examining factors such as fisheries and demographic connectivity. Total diversity at the Caribbean scale was attributed to β-diversity (nearly 62% of the species), with the highest β-diversity at the site scale. α⎯⎯-diversity was higher than expected by chance in all scenarios and at all studied scales.

This suggests that fish assemblages are more homogenous than expected, particularly at the ecoregion scale. Within each ecoregion, diversity was mainly attributed to alpha, except for the Southern ecoregion where there was a greater difference in species among sites. β-components were lower than expected in all ecoregions, indicating that fishes within each ecoregion are a subsample of the same species pool. The scenario involving the effects of fisheries showed a shift in dominance for β-diversity from regions to subregions, with no major changes to the diversity patterns. In contrast, demographic connectivity partially explained the diversity pattern. β-components were low within connectivity regions and higher than expected by chance when comparing between them. The author's results highlight the importance of ecoregions as a spatial scale to conserve local and regional coral reef-fish diversity.

PLoS ONE
8(10): e78761. doi:10.1371/journal.pone.0078761
2013

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