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Discard Mortality of Red Snapper Released with Descender Devices in the U.S. South Atlantic – Runde et al. 2021

Summary:

• 44 red snapper were tagged with electronic transmitters in 120ft of water off of North Carolina.
• Red snapper were released near the seafloor with SeaQualizer, a descender device.
• The tags reported depth and location within a 0.2 mi^2 area.
• Movements of released-alive red snapper were compared to movements of known-dead and recaptured (known-alive) red snapper to determine survival.
• Statistical simulations accounting for hook type (circle vs J) and associated hooking injury found that ~87 percent of all red snapper would survive if released with descender devices.

Effectiveness of descending devices to mitigate the effects of barotrauma among rockfishes (Sebastes spp.) in California recreational fisheries – Bellquist et al. 2019 

Summary:

• Conducted 24 commercial passenger fishing vessel charters at 11 sites and allowed recreational anglers to use 5 different types of descending devices.
• All fish were released to 46m (150’) or to bottom, whichever was shallower.
• Initial post-release mortality was low at 7.5 percent for depths up to 100m and 16.4 percent for capture depths from 100-130m.
• Results suggest rockfishes should be released at least halfway or all the way to the bottom.
• Angler preference for SeaQualizers which had the lowest error rate.

2017 FWC Citizen Science Descending Device Study Final Report

Summary:

• Screening surveys were sent out in June of 2017 and most anglers indicated they did not own a descending device.
• 634 descending devices were mailed out in early July of 2017.
• The SeaQualizer descending device was the most used and the highest rated in terms of satisfaction followed by the Fish Saver, RokLees, and Shelton Fish Descender.
• Most anglers believed devices were successful at descending fish “nearly 100 percent of the time” and “very effective” at increasing survival rates of reef fish suffering from barotrauma.
• Most anglers thought descending devices were easy to use, were likely to continue to use them, and would recommend other anglers to purchase them.

Venting or Rapid Recompression Increase Survival and Improve Recovery of Red Snapper with Barotrauma – Drumhiller et al. 2014

Summary:

• Red snapper survival was assessed in the lab using hyperbaric chambers.
• Capture events were simulated from pressures corresponding to 30m (~100ft.) and 60m (~200 ft.).
• Fish in vented-surface released and rapid recompression treatment groups had the highest survival.
• Both venting and rapid recompression have the potential to increase red snapper survival.

Effectiveness of Venting and Descender Devices at Increasing Rates of Post Release Survival of Black Sea Bass – Rudershausen et al. 2019

Summary:

• 1,748 black sea bass were tagged with t-bar tags off North Carolina.
• Fish were released with one of four methods, in rotation: 1) no treatment; 2) venting with 11-ga cannula; 3) venting with 16-ga needle; and 4) descending to the seafloor with a Blacktip descender device.
• The average increase in survival as compared to fish that were not treated was 48 percent, 51 percent, and 51 percent for the cannula, needle, and descender respectively.
• It is possible to injure a fish with venting, though when applied correctly it can be as effective as descending.
• Barotrauma mitigation via venting or descending results in greatly improved survival of black sea bass.

Recreational Angler Attitudes and Perceptions Regarding the Use of Descending Devices in Southeast Reef Fish Fisheries – Curtis et al. 2019

Summary:

• Surveyed 538 recreational anglers (84 percent private, 15 percent charter, 1 percent headboat) regarding use of fish descending devices in the Gulf of Mexico and South Atlantic.
• 72 percent of respondents had little to no knowledge of descending devices prior to the study.
• 70 percent indicated a preference for descending over venting after provided SeaQualizers.
• 76 percent were likely to continue employing the device.

Quantifying Delayed Mortality from Barotrauma Impairment in Discarded Red Snapper Using Acoustic Telemetry – Curtis et al. 2015

Summary:

• 111 red snapper were tagged with acoustic transmitters over three seasonal trials to assess delayed mortality after release.
• Fish were released with three treatments: non-vented, vented and descended.
• Survival was highest in cooler months and shallower depths.
• Overall survival across all treatments was 72 percent with 15 percent immediate mortality and 13 percent delayed mortality.
• Descended fish were 3 times more likely to survive than non-vented fish and 1.5 times more likely to survive than vented fish.

Venting and Reef Fish Survival: Perceptions and Participation Rates among Recreational Anglers in the Northern Gulf of Mexico – Scyphers et al. 2013

Summary:

• 604 recreational and tournament anglers were surveyed to understand the popularity and perceived effectiveness of venting fish.
• Approximately 2/3 of anglers vent the fish they release offshore and most perceive it to be effective for improving survival.
• Fishing experience did not influence knowledge of proper venting techniques.
• Misinformation on how to properly vent was common among anglers of all experiences.
• Education and outreach programs are necessary to alter or improve venting practices.