Analysis of Fisheries Journals (2021)
A major professional frustration of mine has been the speed with which research results are disseminated. I hypothesized that there exist inherent among-journal differences in turnaround time (from submission to publication). I gathered publication timelines for over 80,000 papers in 82 journals that publish in the field of fisheries science; sure enough, some journals tend to be a lot quicker than others.
Download the data (13 MB .csv file)
Post-release Survival and Barotrauma (dissertation part I)
The continental shelf waters off the southeastern United States are home to over 100 species of demersal (seafloor-associated) fish. When caught, these fish sometimes experience injuries called barotrauma as a result of the pressure change from seafloor to the surface (see gallery). Barotrauma can vary in its severity, but sometimes results in expanded swim bladder gases that cause the fish to float. Unable to re-submerge, floating fish are destined to die without intervention.
Enter descender devices. These handy tools push or pull floating fish back down to a depth where gases recompress. Descender (or descending) devices can be as simple as an inverted milk crate or as complex as the SeaQualizer tool (which has an incorporated pressure sensor allowing a pre-specified release depth). One focus of my research has been evaluating the effectiveness of descender devices in increasing post-release (or discard) survival for a variety of species. We have used conventional and electronic tagging to evaluate survival. Overall, we have shown that descender devices are very effective for increasing survival in several species of groupers, black sea bass, and red snapper.
See a descender device in action below!
Papers on descender devices:
Marine Protected Areas (dissertation part II)
In 2009, the United States designated eight Marine Protected Areas (MPAs) off the southeastern United States. The stated purpose of these MPAs was to protected and rebuild populations of deep-water demersal fishes such as groupers. In the decade (+) since closure, few studies have examined the effectiveness of these areas. My study used a multifaceted approach to evaluate the largest MPA in this network, called the Snowy Wreck Marine Protected Area. We used scientific sonar and biological data collected in 2007-2009 and 2018-2020 to compare fish populations inside and outside this MPA.
We found some positive effects of the Snowy Wreck MPA, including increases in catch rates of economically important species; such increases did not occur in the area outside the MPA. This study is currently in review at Frontiers in Marine Science; please contact me for more information.
Repetitive Captures of Fish (dissertation part III)
Any scientist who has performed a mark-recapture tagging study knows that some animals get caught repetitively. This phenomenon occurs with some regularity in fisheries studies, but it is rarely reported in resulting publications as the initial recapture is often the only one of any consequence. My coauthors and I analyzed four tagging datasets from studies of reef fishes, with the goal of determining the prevalence and impacts of repetitive catch.
We found that repetitive capture is very common in tagging studies, which implies that it happens outside of research as well (particularly in fisheries for which catch-and-release is frequent). This suggests that some measure of abundance that rely on catch data may be biased-high, since a single fish caught multiple times may in fact be counted as multiple fish.
We also found that the proportion of released fish that survive appears to increase for release events 2 or higher. We proposed that this is a result of less-robust individuals succumbing to post-release mortality and more-robust individuals persisting in the tagged population.