Journal Reviews

By Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected] WINNER: 2014 Best Paper, North American Journal of Fisheries Management Phenology is the study of cyclic and seasonal natural phenomena, especially in relation to climate. Although everyone understands it intuitively (imagine looking for the first crocuses emerging from under the snow in your yard), it is one of the least understood impacts of climate change. Adam Peer and T. J. Miller of the Chesapeake Biological Laboratory at the University of Maryland Center for Environmental Science used a time series of Striped Bass Morone saxatilis gill net data obtained during spawning to examine how changes in climate might affect harvest in the fishery, which has a fixed opening date. They found that the onset of spawning was strongly linked with spring temperatures, larger fish spawned earlier, and cool springs increased harvest of larger, egg-bearing females. Thus, climate was linked strongly to fishing mortality in a way that was not accounted for given the fixed opening date. It was a good read, and the in-depth discussion that included spawning-phenology makes it a strong candidate for discussions of recruitment in any fisheries class. REFERENCE Peer, A. C., and T. J. Miller. 2014. Climate change, migration phenology, and fisheries management interact with unanticipated consequences. North American Journal of Fisheries Management 34(1):94-110. dx.doi.org/10.1080/02755947.2013.847877 Members click below for the December 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected] WINNER: 2014 Best Paper, North American Journal of Aquaculture As a practical matter, fish culturists often need to spawn fish artificially, and this is especially true of the catfish industry where hybrids of Blue Catfish Ictaluras furcatus and Channel Catfish Ictaluras punctatus are preferred for growth and disease resistance, but will not spawn naturally. Traditionally spawning has been induced by naturally sourced gonadotrophin releasing hormones (GnRH), although two synthetic analogues are licensed for use. Sylvie Quiniou and her colleagues at the U.S. Department of Agriculture–Agricultural Research Service found a new approach using a novel analogue derived from a different type of GnRH thought previously to play only a secondary role in egg development. Their method resulted in much higher ovulation rates (90.2%) than traditional treatments that usually result in lower rates (44-63%), with no differences in overall egg or fry production. We loved this paper because it has an important practical application, as well as a thoughtful discussion that provides insight into understanding fish spawning physiology. We also wonder if their work might be adapted for other culture situations where maximizing viable egg production is vital. REFERENCE Quiniou, S. M. A., B. Bosworth, N. Chatakondi, and D. Oberle. 2014. Evaluation of a gonadotropin releasing hormone analog of cGnRH II as a spawning aid for Channel Catfish versus analogs of mGnRH I and sGnRH III. North American Journal of Aquaculture 76(3):281-288. dx.doi. org/10.1080/15222055.2014.902889 Members click below for the December 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Jeff Schaeffer | AFS Co-Chief Science Editor The stone crab Menippe spp. fishery is one of the most unusual fisheries in the world, because only claws are harvested, and animals are released to remain in the fishery via survival and claw regeneration. Florida accounts for the majority of landings, and there both claws can be removed if they are of legal size, but the fishery extends into South Carolina where only one legal-sized claw can be removed from a single crab. One of the major drivers of this fishery is the assumption that stone crabs survive claw harvest and regenerate, but Elizabeth Duermit (South Carolina Department of Natural Resources, Marine Resources Research Institute and Grice Marine Laboratory, College of Charleston) and her colleages found that this may not be the case due to both direct and indirect effects. They used a series of elegant experiments to determine that wound widths greater than 7 mm caused high post-removal mortality, and that wound size was more important than if one or both claws were taken. This suggests that fisher skill with claw removal was an important component underlying short-term survival, but there were also long-term effects in that stone crabs with one claw consumed fewer bivalves, and stone crabs with no claws could consume only fish flesh. Restricted feeding could exacerbate an already-long intermolt claw regeneration interval such that few stone crabs return to the fishery. And by examining stone crab claws for sale in retail environments, they found that 20% of the claws exhibited breakage consistent with high short-term mortality. We featured this paper because it was elegant and creative, but also because it is a great example of how some long-held beliefs do not hold up when actually tested. And their work suggests that at least a proportion of mortality depends on fisher skill. The Florida Fish and Wildlife Commission (FFWC) has already established video outreach efforts to teach claw removal (youtube.com/ watch?v=YTgXTS8gLjU), but new knowledge of long-term effects may need to be considered to maintain this fishery, as well as outreach directed at providing science education to Youtube commenters. REFERENCE Duermit, E., P. R. Kingsley-Smith, and D. H. Wilber. 2015. The consequences of claw removal on stone crabs Menippe spp. and the ecological and fishery implications. North American Journal of Fisheries Management 35(5):895-905. dx.doi.org/10.1080/02755947.2015.1064836 Members click below for the November 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Jeff Schaeffer, AFS Co-Chief Science Editor The upper Laurentian Great Lakes were separated physically from the Atlantic coast by Niagara Falls, but constructed ship canals allowed marine invaders to penetrate the system. Invading Sea Lampreys Petromyzon marinus decimated native piscivores during the 1940s, which allowed Alewife Alosa pseudoharengus to proliferate to nuisance levels of abundance by the 1960s. Fisheries managers attacked the Alewife problem by introducing Pacific salmon Oncorhynchus spp. This worked, and created a wildly popular sport fishery that had not existed previously. This was a classic “be careful what you wish for, because you may get it” conundrum. There was some evidence that Alewives were being controlled, and there was tremendous stakeholder pressure to maximize salmon populations because the novel sport fishery was actually revitalizing coastal communities. Indeed, Lakes Michigan and Huron resembled a cornucopia in that there was no apparent upper limit in terms of how many predators could be sustained. However, in 1981, Don Stewart, Jim Kitchell, and Larry Crowder published a Transactions paper that suggested there was an upper limit to how many predators could be sustained. Using bioenergetics modeling (a rather novel concept at that time), they suggested that stocking programs had decoupled predatory demand from prey production, with possible destabilization of the predator-prey system and ultimately strong potential effects on Alewife biomass, with most consumption by Chinook Salmon O. tschawytsha. Their work created a firestorm in that it was the basis for a wide range of subsequent applications of their method to evaluate other predator-prey systems (many of those manuscripts appeared in TAFS), but in the Great Lakes it began a controversy that raged for the next 25 years. There were some managers and researchers who began calling for more judicious stocking rates, while others expressed utter disbelief that a stocking program could actually impact prey dynamics within one of the largest freshwater ecosystems on the planet. No real consensus emerged, but a regional approach developed in which both predators and prey were assessed annually, stocking rates were reduced somewhat from initial levels, and predator-prey dynamics were studied intensively. This approach sustained the salmon fishery until 2004 when Alewife collapsed in Lake Huron, with concurrent decline in Lake Michigan. While there is still some debate regarding the role of climate and invasive effects as contributing factors, salmonid predation was implicated strongly as being severe enough to serve as an absolute slate-wiper for Alewife, with both stocked and feral fish contributing to a high predatory demand. And while salmon controlled a malignant invader, there was an economic burden placed on coastal communities, especially in Lake Huron where fishing effort declined sharply in many areas. On the other hand, Alewife absence was followed by strong recruitment of several native fishes that had experienced chronic low abundance for decades in the presence of Alewife. We love this paper because it was so prescient, and it stimulated a broad range of new research efforts that led to great insight into how models can be useful in understanding predator-prey dynamics. And it began a compelling story about a bold management strategy that led to initial great success, but eventually experienced the most feared and unlikely outcome. REFERENCE Stewart, D. J., J. F. Kitchell, and L. B. Crowder. 1981. Forage fishes and their salmonid predators in Lake Michigan. Transactions of the American Fisheries Society 110(6):751-763. dx.doi.org/10.1577/1548-8659(1981)110<751:FFATSP>2.0.CO;2 Members click below for the November 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected] Management of many fish species requires good recruitment estimates; this is especially true for Gulf Coast reef fishes that are harvested intensively. One of the most important of these is Gray Snapper Lutjanus griseus, which are a primary target of nearshore fisheries in Florida. Gray Snapper have been assessed annually during routine surveys, but Kerry Flaherty-Walia and her colleagues at the Florida Fish and Wildlife Conservation Commission’s Fish and Wildlife Research Institute have discovered a new way to improve estimates by deploying a novel approach in a habitat that had been undersampled. They used a large (183 m) haul seine to sample deep polyhaline seagrass beds and found that they were hotspots for juvenile Gray Snapper; numbers there were greater than obtained from standard surveys, and larger juveniles were abundant. Their data improved confidence in recruitment estimates as well as provided a window into a life stage for which few data were available. But they did this by developing an open-water sampling approach using a gear that had generally been used on shorelines. This is an important article because it not only had a positive outcome for managers concerned with recruitment, but it demonstrates the value of stratified sampling across habitats and, most of all, the value of deeper seagrasses as habitat, not only for Gray Snapper, but other fishes as well. Their work also makes us think that haul seines would be useful sampling techniques in other habitat types. REFERENCE Flaherty-Walia, K. E., T. S. Switzer, B. L. Winner, A. J. Tyler-Jedlund, and S. F. Keenan. 2015. Improved ability to characterize recruitment of Gray Snapper in three Florida estuaries along the Gulf of Mexico through targeted sampling of polyhaline seagrass beds. Transactions of the American Fisheries Society 144:911-926. dx.doi.org/10.1080/00028487.2015.1054516 Members click below for the October 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected] Ethanol production has increased 13-fold from 2000 to 2013, and this has resulted in a concurrent increase in distillers dried grains (DDG), which are a byproduct of the fermentation process. While long used as feed for cattle, they have not been used widely in aquaculture due to mycotoxins present in the product. Wendy Sealey (U.S. Fish and Wildlife Service, Bozeman Fish Technology Center) and her colleagues used feeding trials with or without a mycotoxin deactivation product (Biofix Plus) to examine growth and food conversion of Oncorhynchus mykiss fed traditional diets containing fish meal, and a group in which 12% of the fish meal was replaced by DDG. They found no performance differences between traditional diets and those containing DDG. They also concluded that at 12% replacement mycotoxins did not need to be deactivated at all and were likely not an issue at that substitution rate. The North American Journal of Aquaculture continues to feature articles that push the boundaries of shifting cultured organisms away from fish meal diets, and this paper is an excellent and well-written example of that trend. We do note that one hypothetical outcome of this article is a dinner at a microbrew pub in which the beverage is obtained from fermentation, and the fish dinner might be obtained at least partially from the same process! REFERENCE Sealey, W. M., C. G. Hooley, K. A. Rosentrater, T. Gibson Gaylord, and F. T. Barrows. 2015. The effect of a mycotoxin deactivation product on growth of juvenile Rainbow Trout fed distillers dried grains. North American Journal of Aquaculture 77:429-436. dx.doi.org/10.1080/152 22055.2015.1029175 Members click below for the October 2015 Fisheries magazine’s complete issue. Non-members, join here.

When you think of a national park, you probably have a vision of a place that is mostly pristine and untouched. So when Parks Canada took on the task of trying to eradicate the invasive Brook Trout Salvelinus fontinalis from the Middle and Lower Devon lakes, which form part of the headwaters of the Clearwater River in Banff National Park, they took into consideration the public’s notion of what a national park should be: a protected area, free of chemicals. For more than 70 years, piscicides (e.g., rotenone and antimycin) have been used to eradicate fish species (McClay 2000); however, their use has legal and social implications (Finlayson et al. 2000). In the North American Journal of Fisheries Management, Charlie Pacas and Mark K. Taylor of Parks Canada were able to show how mechanical methods can be an effective method for trout eradication in lotic and lentic environments. In the upper part of Clearwater River, they used electrofishing to target non-native Brook Trout, and in the two Devon lakes, they used gillnetting as well as shoreline electrofishing. Then after the last fish were caught in the lakes and river, they conducted postremoval monitoring using the same methods to confirm their findings. To date, most fish removal projects using only mechanical methods have failed to demonstrate 100% effectiveness, especially projects of this size. The authors credit their success to the simple morphology of the alpine lakes and river (both lacked structure such as vegetation that could prevent fish capture) as well as the intensity of their effort. REFERENCES Finlayson, B. J., R. A. Schnick, R. L. Cailteux, L. DeMong, W. D. Horton, W. McClay, C. W. Thompson, and G. J. Tichacek. 2000. Rotenone use in fisheries management: administrative and technical guidelines manual. American Fisheries Society, Bethesda, Maryland. McClay, W. 2000. Rotenone use in North America. Fisheries 25(4):15-21. Pacas, C., and M. K. Taylor. 2015. Nonchemical eradication of an introduced trout from a headwater complex in Banff National Park, Canada. North American Journal of Fisheries Management 35:748–754. dx.doi.org/10.1080/02755947.2015.1043412 Members click below for the October 2015 Fisheries magazine’s complete issue. Non-members, join here.

As an anadramous species, Atlantic Salmon Salmo salar have a complex life history that includes spending part of their lives in freshwater, estuarine, and marine habitats. In recent years, the decline of Atlantic Salmon has been attributed to their poor marine survivorship, due in large part to climate change. However, factors contributing to their marine mortality do not operate independently of factors acting in estuarine and fresh waters. Therefore, an understanding of all the factors that influence mortality could help to enhance Atlantic Salmon management. In a new study in Marine and Coastal Fisheries, Daniel S. Stich of the University of Maine and his colleagues examined the behavior and survival of Atlantic Salmon smolts during estuary migration in the Penobscot River, using surgically implanted acoustic tags, between 2005 to 2013. They examined three main categories of potential drivers for behavior and survival: (1) individual fish characteristics (fork length, mass, condition factor), (2) migratory history (number of dams passed, migratory route), and (3) environmental variability (cumulative temperature experienced). Of all the drivers tested, the one that most affected a smolt’s chances of survival was the number of dams it passed during its estuary migration. For every dam a salmon passed, its survival decreased by 6-7%, and the effects were cumulative. In the study, most salmon passed between two and nine dams. The authors also found that smolt survival during migration increased by up to 25% if they entered the estuary at their peak physiological preparedness (i.e, fish with the highest gill Na+, K+ -ATPase activity). These findings can help hatchery mangers decide when to release their smolts in order to increase survival. REFERENCE Stich, D. S., G. B. Zydlewski, J. F. Kocik, and J. D. Zydlewski. 2015. Linking behavior, physiology, and survival of Atlantic Salmon smolts during estuary migration. Marine and Coastal Fisheries 7:68-86. dx.doi.org/10.1080/19425120.2 015.1007185 Members click below for the October 2015 Fisheries magazine’s complete issue. Non-members, join here.

By Sarah Harrison | AFS Contributing Editor. E-mail: [email protected] Clifford Hutt (Mississippi State University, Human Dimensions and Conservation Laboratory) and his colleagues estimated both the economic impact (the monetary benefits of angling to the regional economy) and economic value (the value of a fishing trip above the angler’s actual costs; their net “willingness-to-pay” for the resource) of recreational fisheries for crappie Pomoxis spp. in Mississippi and showed how this data could be paired with exogenous variables (i.e., reservoir water level, water temperature) to assess the costs of different management actions. In the article, the authors specifically examined how changes in spring water levels affected the number of fishing trips taken, which affected total angler expenditures and economic value. They found that angling effort and economic impact and value peaked at intermediate water levels and declined at both low and high water levels. The authors state that information on the economic benefits of fisheries is important to fisheries management, especially in the face of competing demands and climate change. Research on climate change is too often narrowly focused on biological systems, ignoring fishers and how they respond to a variety of changing economic, institutional, and environmental conditions. This article shows how fishers can be incorporated into analyses and predictions in order to assess policy changes. REFERENCE Hutt, C. P., K. M. Hunt, S. F. Steffen, S. C. Grado, and L. E. Miranda. 2013. Economic values and regional economic impacts of recreational fisheries in Mississippi reservoirs. North American Journal of Fisheries Management 33:44–55. dx.doi.org/10.1080/02755947.2012.739986