2017

Green, SJ, E Underwood, and JL Akins

Lionfish derbies and tournaments were first implemented in 2009 with the intent of increasing public awareness about the lionfish invasion in the western Atlantic, gathering specimens for research, and training volunteers to safely and effectively collect the venomous species. Since then, REEF has coordinated a series of derbies each year and assisted other organizations and groups in organizing and running their own derbies, resulting in the removal of tens of thousands of invasive lionfish.

The increasing number of derbies held across the region presents an excellent opportunity to investigate the extent to which volunteer removal activities during such derbies can be an effective means of population suppression. Using REEF lionfish derbies as a test case, REEF staff, affiliated scientists, and volunteers worked together to address six key questions: 1) What is the total area over which removal can be affected during a derby event? 2) Is capture during derbies size-selective? 3) To what extent are local invader populations suppressed by derby activities? 4) At what rate do lionfish re-colonize following derby events? 5) Is removal sufficient to reduce and sustain densities below those predicted to cause predation-mediated declines in native species? and 6) Is the magnitude of invader removal related to catch per unit effort (CPUE)? To answer these questions, the authors collected data on landings and participant effort over three years of lionfish derbies in both Key Largo, Florida and Green Turtle Cay, Bahamas.

The study documented that from 2012-2014, single day derbies reduced lionfish densities by 52% across an area of 192 km2 on average each year. Differences in recolonization and productivity between regions meant that annual events were sufficient to suppress the invasion below levels predicted to cause declines in native species in one region, but not the other. Population reduction was not related to CPUE, confirming the importance of in situ monitoring to gauge control effectiveness. Future work to assess rates of recolonization in relation to derby frequency will help guide management and control decisions.

Conservation Letters
DOI: 10.1111/conl.12426
2017
Program: 
Invasive Species Program
Tolimieri, N, EE Holmes, GD Williams, R Pacunski, and D Lowry

Estimating a population’s growth rate and year-to-year variance is a key component of population viability analysis (PVA). However, standard PVA methods require time series of counts obtained using consistent survey methods over many years. The authors of this study used REEF data along with two other fisheries datasets to evaluate the long-term trends of rockfish in Puget Sound, Washington State. The time-series analysis was performed with a multivariate autoregressive state-space (MARSS) model. The authors show that using a MARSS modeling approach can provide a rigorous statistical framework for solving some of the challenges associated with using multiple, sometimes inconsistent datasets, and can reduce the proportion of fisheries assessment cases that are assigned a designation of “data deficient.”

The analysis of the paper was part of the 5-year review of the Endangered Species Act (ESA) listing of Puget Sound populations of three rockfish species (Bocaccio, Canary Rockfish, and Yelloweye Rockfish), and was conducted by scientists at the National Marine Fisheries Service and Washington Department of Fish and Wildlife. The three sources of data included in the study were: (1) recreational catch data, (2) scuba surveys conducted by REEF surveyors, and (3) a fishery-independent trawl survey. Because there were too few observations of the three species of rockfish in the data sources to analyze these species directly, the MARSS analysis estimated the abundance of all rockfish. Because Bocaccio, Canary, and Yelloweye are deep water species, they are not often seen by REEF surveyors. The other two data sets showed that these rockfishes declined as a proportion of recreational catch between the 1970s and 2010s. The REEF data suggest that other species like Copper and Quillback rockfish have experienced population growth in shallower depths.

Ecology and Evolution
7: 2846–2860. https://doi.org/10.1002/ ece3.2901
2017
Program: 
Volunteer Fish Survey Project
Gruss, A., JT Thorson, EA Babcock, and JH Tarnecki

In this paper, authors use data regarding where REEF divers did or did not encounter three species of fisheries importance: red snapper, red grouper, and gag grouper. They then combined these data with 36 other data sets, each sampling different areas of the Gulf of Mexico, and created distribution maps for use in ecosystem models of the Gulf of Mexico. These distribution maps picked up fish hotspots that are not identifiable by any individual data set, highlighting the complementary nature of the REEF data.

ICES Journal of Marine Science
doi:10.1093/icesjms/fsx120
2017
Program: 
Volunteer Fish Survey Project
Clauson-Kaas, S, K Richardson, C Rahbek, and BG Holt

The study used REEF's Volunteer Fish Survey Project database to produce a new map of marine fish biodiversity across the Caribbean and tropical western Atlantic. The work, performed by scientists from the Center for Macroecology, Evolution & Climate in Denmark and the Marine Biological Association, studied REEF’s extensive data base collected by our volunteer surveyors to produce the map and find that fish biodiversity is strongly linked to sea temperatures. However, results also show that while fish biodiversity is higher in warmer waters, the very hottest sites in fact have fewer species than sites with intermediate temperatures, something not shown before in previous studies. These results will be of concern given the rising water temperatures in the region. For more details, see this REEF enews article.

Journal of Biogeography
2017(00): 1–11
2017
Program: 
Volunteer Fish Survey Project
Roberts M, N Hanley, S Williams, and W Cresswell

REEF fish survey data collected from Bonaire in 2015 were used to help evaluate the impact of terrestrial degradation on nearby coral reefs, specifically investigating the link between vegetation ground cover and tree biomass index to coral cover, fish communities and visibility. The authors found a positive relationship between ground cover and coral cover below 10 m depth, and a negative relationship between tree biomass index and coral cover below 10 m. Greater ground cover is associated to sediment anchored through root systems, and higher surface complexity, slowing water flow, which would otherwise transport sediment. The negative relationship between tree biomass index and coral cover is unexpected, and may be a result of the deep roots associated with dry-forest trees, due to limited availability of water, which therefore do not anchor surface sediment, or contribute to surface complexity. The analysis provides evidence that coral reef managers could improve reef health through engaging in terrestrial ecosystem protection, for example by taking steps to reduce grazing pressures, or in restoring degraded forest ecosystems.

Ocean & Coastal Management
149 (5): 52-68
2017
Program: 
Volunteer Fish Survey Project
Starck, WA, Estapé CJ & Morgan Estapé, A

From 1958-67, Walter A. Starck II conducted marine biological studies in the area of Alligator Reef, off of Islamorada in the Florida Keys, these included extensive fish collecting. In 1968, he published A list of fishes of Alligator Reef.

Over the half-century since the original Alligator Reef survey, there have been great advances in the taxonomy of Greater Caribbean reef fishes, with numerous changes in scientific names and classification. As part of the update these changes are addressed so as to bring the list to current status.

In 2013 the junior authors (REEF Advanced Assessment Team members) undertook a four-year census of the fishes of the area with a goal to photo-document as many of their sightings as possible. This effort has subsequently entailed 1039 combined dives devoted to fish counts, photographic documentation, or both. During these surveys, they have photographed 278 of the species reported by Starck (1968) plus 35 additional and/or newly described or reclassified species not recorded in the earlier study.

An update of the checklist of fishes of Alligator Reef and environs some fifty years later provides an unparalleled opportunity to evaluate the species richness for a limited reef area, as well as a unique opportunity to explore changes in diversity over a half-century time scale. In the updated study the authors added 107 species and subtracted 5 from the original total of 516 species: thus the checklist now totals 618 species, of 122 families, the most recorded for any similarly sized area in the New World. The additional species records are made up from a number of subsequent collections as well as from a comprehensive effort by the junior authors.

Among the other databases of relevance to the study area used for comparison, the Smithsonian Tropical Research Institute (STRI) Shorefishes of the Greater Caribbean by D.R. Robertson & J. Van Tassell and that of the Reef Environmental Education Foundation (REEF).

REEF maintains an online database of worldwide visual fish-count surveys conducted by volunteer researchers and fish-count enthusiasts. While such surveys are biased towards easily observed species, they are indicative for a large portion of the reef fish fauna and comprise a valuable source of comparative information (Schmitt & Sullivan 1996, Pattengill-Semmens & Semmens 2003, Holt et al. 2013). The local REEF data includes that of the Estapés, who have conducted 185 roving-diver REEF surveys on Alligator Reef. An additional 1807 surveys at 94 sites in the study area have also been conducted by other REEF volunteers (as of July, 3, 2016).

Journal of the Ocean Science Foundation
27
2017
Program: 
Volunteer Fish Survey Project
Beattie, M, DP Nowacek, AK Bogdanoff, L Akins, and JA Morris

Through the analysis of acoustic recordings of captive Pterois spp., this study has confirmed anecdotal evidence that Pterois spp. are soniferous. This report of sound production in Pterois spp. provides the foundation for future research into their specific acoustic capabilities including sound production mechanisms, the role of social behaviour and applied techniques for controlling and monitoring invasive Pterois spp. in the tropical and temperate western Atlantic Ocean. REEF staff, Lad Akins, was a co-author.

Journal of Fish Biology
90(6), 2488-2495
2017
Program: 
Invasive Species Program

2016

Bernard, AM, KA Feldheim, R Nemeth, E Kadison, J Blondeau, BX Semmens, MS Shivji

Like many places throughout the Caribbean, Nassau Grouper spawning aggregations in the US Virgin Islands were overfished until their disappearance in the 1970s and 1980s. In the early 2000s, however, Nassau Grouper were found gathering at Grammanik Bank, USVI, a mesophotic coral reef adjacent to one of the extinct aggregation sites, and regulatory protective measures were implemented to protect this fledgling aggregation. The authors of this study addressed two objectives: 1) which factors (local vs. external recruitment) are important in shaping recovery of the USVI spawning aggregations, and 2) the impact of severe past overfishing on the genetic structure of the Gremmanik Bank aggregation. For this second objective, REEF Grouper Moon Project scientists provided genetic samples from individual Nassau Grouper taken from the Little Cayman spawning aggregation, a much larger and less impacted aggregation.

No population structure was detected between the USVI and Cayman spawning aggregations. Additionally, the USVI spawning population showed signs of a genetic bottleneck, typical of greatly reduced populations. These collective results suggest that external recruitment is an important driver of the USVI spawning aggregation recovery. These findings also provide a baseline for future genetic monitoring of the spawning aggregations.

Coral Reefs
35:273–284
2016
Program: 
Grouper Moon Project
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
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

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