My research investigates how rockfish respond physiologically to barotrauma stress.
Rockfishes are heavily utilized in commercial and
recreational fisheries and several have been listed as “overfished” by
the Pacific Fishery Management Council.
As a result of long generation times in rockfishes, recovery of
these populations are expected to be slow.
Of even greater concern, is that apart from basic life history,
very little is known about rockfishes.
Currently, much of the mortality among overfished rockfish is from
bycatch. Because rockfishes
have a closed swim bladder and are often caught at depths exceeding 30 m,
most species experience moderate to severe barotrauma when brought to the
surface. Overfished species
are discarded as is required by regulations, but mortality is typically
assumed to be 100%.
Recent videotaped experiments to recompress rockfish using a cage to lower them back to depth have had promising results, however little is known about what happens to these fish after they are released. How does internal damage affect their normal ability to function, and can these fish fully recover from barotrauma? These are questions I hope to answer through the use of histology, analyses of cortisol and tissue repair enzymes in the blood, blood gas analyses, and gene expression analyses. By understanding the physiology of barotrauma, more effective release techniques can be developed to assist in the recovery of overfished rockfish species, and we can provide fishermen with a greater understanding of how to help in the recovery of overfished populations.
Alena L. Pribyl