2016

Devastating transboundary impacts of sea star wasting disease on subtidal asteroids

Montecino-Latorre, D, ME Eisenlord, M Turner, R Yoshioka, CD Harvell, CV Pattengill-Semmens, JD Nichols, and JK Gaydos

Sea star wasting disease has devastated sea star populations on the West coast from Mexico to Alaska. The disease broke out in 2013, causing massive death of several species of sea stars. Infected animals develop lesions that eat away tissue, with limbs dropping off as the animals die. The disease has been linked to a virus, although environmental factors may also be involved. This study presents an analysis of REEF survey data on several asteroid species collected by divers in the Salish Sea over the last 15 years.

The results showed that some species were hit hard, while others increased in number. Populations of sunflower sea star (Pycnopodia helianthoides), an important keystone predator in the region, dropped dramatically after the beginning of the epidemic. Several other sea star species, including the spiny pink star (Pisaster brevispinus) also declined. Numbers of the less-common leather star (Dermasterias imbricate) and two species of sea urchin, which are prey for sea stars, increased after 2013.

The virus outbreak continues, and will have lasting effects on the ecosystem. Sunflower sea stars have effectively disappeared from the Salish Sea, the study concludes. Likely as a result, numbers of urchins have increased, which in turn will lead to more browsing on kelp. As a result, study co-author, Dr. Joe Gaydos, and his colleagues are currently in discussions with the National Marine Fisheries Service to get the sunflower sea star listed as a “species of concern.”

PLoS ONE
11(10): e0163190. doi:10.1371/journal.pone.0163190
2016
Program: 
Volunteer Fish Survey Project
Link to PDF article

Evidence for a trophic cascade on rocky reefs following sea star mass mortality in British Columbia

Schultz​, JA, RN Cloutier, IM Côté

The US Pacific Northwest and western Canada experienced a mass mortality of sea stars between 2013 and 2015. The sunflower star (Pycnopodia helianthoides), a previously abundant predator, began to show signs of a wasting syndrome in early September 2013, and dense aggregations disappeared from many sites in a matter of weeks. REEF surveyors certainly noticed, and the decline was reflected in the REEF database. The authors used the REEF database to document the decline regionally, along with a four-fold increase in the number of green sea urchins (Strongylocentrotus droebachiensis). The sea urchin increase also resulted in declines in kelp canopy coverage. This type of ecological change or trophic cascade, is where a change in one species impacts many others. Because of the long-term and wide-spread nature of the REEF survey program, our data have proven invaluable in documenting the impacts of the seastar wasting disease.

PeerJ
4:e1980
2016
Program: 
Volunteer Fish Survey Project
Link to PDF article

Lionfish: a major marine invasion

Hixon, MA, SJ Green, MA Albins, JL Akins, and JA Morris Jr.

This paper is the introduction to a special issue of the journal, Marine Ecology Progress Series, titled "Invasion of Atlantic coastal ecosystems by Pacific lionfish". The issue is a compilation of papers presented at the 2015 special session of the Gulf and Caribbean Fisheries Institute meeting, which was co-organized by REEF and partner organizations. New findings include mechanisms that enhance the success of the invader, the extremely broad and variable diet of invasive lionfish, the ecological effects of the invader on native fish populations in various environmental contexts, and non-consumptive interactions between invasive lionfish and native predators. The entire issue is available online at http://www.int-res.com/abstracts/meps/v558/#theme.

Marine Ecology Progress Series
Vol. 558: 161–165, doi: 10.3354/meps11909
2016
Program: 
Invasive Species Program
link to PDF article

Managing marine invasive species through public participation: Lionfish derbies as a case study

Luis Malpica-Cruza, L, LCT Chavesa, IM Côté

The authors of this study examined drivers of public involvement and success at invasive removal in tournaments (derbies) to catch Indo-Pacific lionfish (Pterois volitans/miles) in the Western Atlantic. Information on 69 lionfish derbies held in the wider Caribbean region from 2010 to 2015 was compiled, including REEF Lionfish Derbies. The authors found that the number of lionfish caught increased with effort and with time since lionfish were established in an area. They also found that derby participation was best predicted by national wealth (GDP per capita) and number of local dive shops. These findings support that, from the point of view of public engagement, derbies should be held in areas where lionfish are well established, and where the pool of potential participants is large. However, alternative strategies may be more effective in areas where few lionfish are present.

Marine Policy
74 (December 2016): 158–164
2016
Program: 
Invasive Species Program
link to PDF article

The non-native royal damsel (Neopomacentrus cyanomos) in the southern Gulf of Mexico: An invasion risk?

Johnston, M.W and J. L. Akins

A diminutive, non-native damselfish (Neopomacentrus cyanomos) was recently discovered inhabiting coral reefs near Veracruz, Mexico—far removed from where it is native in the Red Sea and the Indo-Pacific. This publication, co-authored by REEF's Director of Special Projects, Lad Akins, evaluates the threat of establishment and spread in the invaded range.

The quantities found in the Gulf of Mexico (GOM) suggest that the fish has already established a self-sustaining population in this new ecosystem. There is understandable concern, therefore, that this new arrival may become invasive and spread, yet the invasion risk imposed by this fish has not been assessed. In this study, a computer model was employed to deliver a forecast of the potential range of incursion of the damselfish in the GOM spanning 5 years. The model incorporated oceanic water flow in the region, tolerances of this damselfish to the ocean environment, and their reproductive strategy in order to supply a temporal and spatial forecast of their spread. From this study, targeted early detection and removal of the fish can be directed if the fish is deemed a threat to native fauna. On the basis of this work, it is foreseeable that the reefs presently harboring Regal Damselfish will likely see increased abundance of this damsel. Immediate attempts to eliminate the fish, therefore, should be focused in nearshore shallow waters spanning Veracruz to Frontera, Mexico. Further, water flows in the southern GOM are not widely conducive to long-distance transport of marine organisms with pelagic larvae, reducing the risk of this damsel permeating the greater GOM over 5 years. Aside from Regal Damselfish, this study implicitly adds to mounting evidence supporting a biogeographic disconnect between the Veracruz reef complex and the greater GOM and the Caribbean.

REEF surveyors are on the lookout for Regal Damselfish in the Gulf of Mexico and western Caribbean.

Marine Biology
163: 12
2016
Program: 
Invasive Species Program
PDF

2015

Lifting the goliath grouper harvest ban: Angler perspectives and willingness to pay

Shideler, GS, DW Carter, C Liese, JE Serafy

Despite uncertainties surrounding the population status of the protected Atlantic Goliath Grouper’s, fishery managers are under pressure to end the harvest moratorium in place since 1990. This study sought to measure the proportion of anglers interested in reopening the goliath grouper fishery and to identify key reasons for this interest. The authors also estimated the amount that anglers would be willing to pay for a Goliath Grouper harvest tag (the right sold to an angler to harvest one goliath grouper). REEF data on Goliath Grouper were used to compare with the fishermen-perceived grouper population trends. REEF data have been cited as the best available index of abundance for Goliath Grouper in Florida (see Koenig et al., 2011, http://www.REEF.org/db/publications/9754). The study found that about half of Florida’s recreational anglers believe that the ban on fishing for goliath grouper should be lifted, with many anglers reporting that they feel "there are too many goliath grouper and that their populations need to be controlled." These anglers are willing to pay between $34 and $79 for the right to harvest one goliath grouper in Florida.

As fishery managers work to determine the future of goliath grouper in Florida and the rest of the southeast United States, this study's findings can help them better understand stakeholder intentions and better communicate to the public. Additionally, fishery managers can compare the amount of money recreational anglers are willing to pay to open the fishery to the amount of money other stakeholders, such as recreational divers who visit goliath grouper, are willing to pay to keep the fishery closed.

Fisheries Research
Volume 161 (January 2015): 156–165
2015
Program: 
Volunteer Fish Survey Project
PDF

Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale

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
Program: 
Volunteer Fish Survey Project
Paper PDF

2014

Demographic Modeling of Citizen Science Data Informs Habitat Preferences and Population Dynamics of Recovering Fishes

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
95 (12): 3251-3258. dx.doi.org/10.1890/13-2223.1
2014
Program: 
Volunteer Fish Survey Project
PDF

Evaluation of rockfish conservation area networks in the United States and Canada relative to the dispersal distance for black rockfish (Sebastes melanops)

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
Program: 
Volunteer Fish Survey Project
Online PDF

Hot Moments in Spawning Aggregations: implications for ecosystem-scale nutrient cycling

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
Program: 
Grouper Moon Project

Pages