What Fish Should I Eat? by Don Orth

Fisheries and aquaculture provide protein for a quarter of the world’s population and livehoods for 59.6 million workers. Fish provide a high-quality, easily digested animal protein with essential amino acids, fats, and micronutrients. Greater consumption of fish is associated with a lower risk of dementia, cognitive decline, and cardiovascular disease (Bakre et al. 2018; Marshall and van der Meij 2018).  Eat more fish - it's good for you!  Yet, the diversity of fish and types of fishing makes the selection of what fish to eat more complicated. 

Tuna is a popular food fish worldwide.  Photo by Ashbridge Studios, CC BY-NC-ND 2.0.  Source

One of many challenges to reducing hunger and malnutrition is to eliminate overfishing and delivering seafood in sustainable manner that does not further contribute to climate change.  Globally, 67% of assessed fish stocks are within biologically sustainable levels, which means they are at or above the level associated with maximum sustainable yield (FAO 2018); however, more fish stocks are being overfished.

Global trends in the state of the world’s marine fish stocks, 1974-2015.   Source:  FAO 2018.  CC-BY-NC-SA        

Fish and fish products provide an average of only ~34 calories per capita per day but the daily contribution varies widely by region based on availability of alternative protein sources and cultural preferences for fish.  Annual per capita consumption has more than tripled since 1961 in developing regions where four fish dominate our menu — salmon, sea bass, cod, and tuna (Greenberg 2011).   Many low-income regions of Latin America and Africa, where political instability and civil unrest have stymied economic development, still have very high food deficits.

Contribution of fish to animal protein supply (2013-2015).   Source:  FAO 2018.  CC-BY-NC-SA    

More people are consuming fish than ever before. The admonition to “think global and act local” should translate to eating locally harvested seafood and minimizing costs and unsustainable fishing practices. The Code of Conduct for Responsible Fisheries (FAO 1995) is a guiding framework for implementing sustainable fisheries and aquaculture operations. It sets out international principles and standards of behavior to ensure effective conservation, management, and development of both marine and freshwater living aquatic resources. It also accounts for the impact of fishing on ecosystems, the impact of ecosystems on fisheries, and the need to conserve biodiversity.    

Sustainability is a plastic word (Nikiforuk 2019). A fishery is not simply sustainable or not sustainable.  It’s more complicated and requires many choices.  Most practitioners accept three dimensions of sustainability: social, economic and ecological, but a deeper analysis requires consideration of six dimensions of sustainable development, specifically economic, social, ecological, institutional, ethical, and technological factors (Lam and Pitcher 2012; Aquado et al. 2016). For example, justice relates to equity or the fair distribution of benefits and harm, in terms of ecosystems and social justice. Many issues play into assessing sustainability.  Globally, we should be concerned with issues of seafood safety, bycatch, fish fraud, pollution from fish farms, post-harvest loss and waste, local governance, microplastics, lost and discarded fishing gear, overharvest of forage fish harvesting for fish meal, and many other social and ethical issues. As the trade flow diagrams show us, the source of our seafood is also complicated and most regions are importing much of their seafood. Your choice of fish to eat may depend on where and how it was harvested. 

Trade flows of fish and fish product by continent, share of total imports in value 2016 (%).  Source:  FAO 2018.  CC-BY-NC-SA        

Seafood certification, or ecolabeling, provided by third-parties, such as the Marine Stewardship Council and Seafood Watch, are the beginnings of evaluation of ethical and sustainble fisheries. Fishing practices changed dramatically in response to public outrage over harvest of dolphins in tuna purse-seining.  Fisheries that meet Marine Stewardship Criteria are highly selective for the target species, have limited access, well regulated, enforced, and often involve co-management between government, scientists, and fishers.  Seafood Watch develops fisheries and aquaculture standards to judge and communicate fish to “avoid” and “good” or “best” choices.  A novel aspect of this program rates whether fisheries support human trafficking, forced labor or child labor, as well as a new tool that collects data on carbon emissions (Monterey Bay Aquarium 2018).  These third-party certifications of sustainability have not yet delivered on the promise of price premiums, improved governance, or improved environmental conditions (Roheim et al. 2018). Challenges remain in the implementation of seafood sustainability due to potential for confusion about the overlapping goals of a growing range of sustainability initiatives (McClenachan et al. 2016).  

Three types of seafood sustainability initiatives and example goals of each (McClenachan et al. 2016).

One of the remaining issues of ecosystem justice remains to be solved.  With the expansion of aquaculture, the demand for fish meal has increased.   Small fishes, menhaden, anchovies, sardines, capelin, herring, and others are harvested and sent to reduction facilities that market and sell food to fish and other farms.   These fish, often labeled as forage fish, when overfished, no longer support seabirds and larger striped bass or bluefin tuna at higher trophic levels. 

What fish should I eat?  You can eat the fish you catch locally after you learn about local fish consumption advisories.  Take time to learn more about the fish you purchase to eat and how they were harvested.  Alaska Pollock Theragra chalcogramma had the highest catch of any fish in the world, followed by anchoveta, and Skipjack Tuna Katsuwonus pelamis.   Pollock is a “best choice” option according to Seafood Watch, but the Marine Stewardship Council has certified only the US fisheries for Alaska Pollock. McDonald's Filet-O-Fish contains Alaska Pollock in North America.   Skipjack Tuna is a “best choice” if harvested by trolling or pole-and-line fisheries, whereas the long line and purse seine fisheries is a “good choice” due to concerns of bycatch of dolphins. Tuna fisheries that use purse seines with FAD (fish attraction devices) should be avoided.   How do you know?   Look for the Marine Stewardship Council logo on any fish you purchase. 

I also started to compare the carbon foot prints of wild versus farmed seafood. The Seafood Carbon Emissions Tool was created by scientists at the Monterey Bay Aquarium Seafood Watch program and Dalhousie University. This tool also allows you to calculate the emissions associated with transporting the product to its final destination.   Most highly valued species such as shrimp, prawns, salmon, tunas, groundfish (e.g., cod, hakes, and haddocks), flatfish, seabass, and seabream are traded to the most prosperous markets, while less valued species are exported to developing countries. The US imports 98% of its Atlantic Salmon.  My favorite wild Alaskan Sockeye Salmon turns out to have a very high carbon cost associated with transport  

Since aquaculture provides over 50% of global seafood and the US imports the majority of its edible seafood, expect the supply of farmed seafood to continue to increase.  Hopefully, more of these products will be marketed with third party certification to assure responsible practices. Look for the logo for Best Aquaculture Practices Certification.  Watch for locally grown seafood from farms that use recirculating aquaculture technology and integrate aquaponics with fish production.  A land-based aquaponics farm, Superior Fresh, is expanding operations in Wisconsin on a 720-acre property producing fish and leafy green vegetables.  Superior Fresh is the first land-based Atlantic Salmon producer and the world’s largest aquaponics facility.  The goal is to producing seafood with a smaller environmental footprint than other options.  At a recent Wisconsin Aquaculture conference,  Greg Fischer, Manager of the Northern Aquaculture Demonstration Facility, predicted that Walleye “will be the next big food fish for aquaculture in the Midwest.”  This locally produced fish would reduce demand on wild stocks. 

References

Aguado, S.H., I.S. Segado, and T.J. Pitcher.  2016. Towards sustainable fisheries: A multi-criteria participatory approach to assessing indicators of sustainable fishing communities: A case study from Cartagena (Spain). Marine Policy 65:97-106.

Bakre, A.T. and thirteen coauthors. 2018.  Association between fish consumption and risk of dementia: a new study from China and a systematic literature review and meta-analysis.  Public Health Nutrition 21(10):1921-1932.

FAO. 1995. Code of Conduct for Responsible Fisheries. Rome.  Accessed 17 June, 2019 from http://www.fao.org/3/v9878e/v9878e00.htm

FAO. 2018. The State of World Fisheries and Aquaculture 2018 - Meeting the sustainable development goals. Food and Agriculture Organization of the United Nations, Rome, Italy.  227 pp.  Accessed 17 June, 2019 from http://www.fao.org/documents/card/en/c/I9540EN

Greenberg, P. 2011.  Four Fish: The Future of the Last Wild Food.    Penguin Books, 285 pp. 

Lam, M.E., and T.J. Pitcher. 2012.  The ethical dimensions of fisheries.  Current Opinion in Environmental Sustainability 4:364-373.

Marshall, S., and B. van der Meij. 2018.  Fish and omega-3 intake and health in older people.   Maturitas 115:117-118. 

McClenachan, L., S.T.M. Dissanayake, and X. Chen. 2016. Fair trade fish: consumer support for broader seafood sustainability.  Fish and Fisheries 17:825-838.

Monterey Bay Aquarium. 2018.  Monterey Bay Aquarium Seafood Watch Launches First-of-its-Kind Seafood Slavery Risk Tool.    Accessed 17 June 2019 from https://newsroom.montereybayaquarium.org/press/seafood-watch-launches-seafood-slavery-risk-tool

Nikiforuk, A. 2019.  Against ‘sustainability’ and other plastic words.  The Tyee  2 May. Accessed on 18 June at https://thetyee.ca/Opinion/2019/05/02/Sustainability-Plastic/

Roheim, C.A., S.R. Bush, F. Asche, J.N. Sanchirico, and H. Uchida. 2018. Evolution and the future of sustainable seafood market.  Nature Sustainability 1:392-398.

Hoki Fish: A Potential Fishy College Mascot? By Don Orth

What college has the dumbest mascot?   This Bleacher Report post includes the Virginia Tech Hokies among the 23 dumbest mascots.  (Full Disclosure, I have two degrees from Oklahoma State University where the mascot for the Cowboys is a crusty old cowboy named Pistol Pete.  Before Pistol Pete, they struggled for 35 years as Agriculturists or Aggies, the Farmers, and officially but unpopularly, the Tigers)    I am not a big fan of these lists and rankings. This post makes me wonder who David Luther is and what criteria and evidence he used to develop the list.  But Mascots can and do change.  There may be a new fish in Virginia Tech's future.

Virginia Tech’s original mascot, the Gobbler, was so lame that it was eventually replaced by the Hokie.  But what's a hokie, you ask? The name comes from an early 20th century cheer.

Hoki, Hoki, Hoki, Hy.
Techs, Techs, V.P.I.
Sola-Rex, Sola-Rah.
Polytechs - Vir-gin-ia.
Rae, Ri, V.P.I.

The Hokie bird mascot, resembling a maroon and orange turkey-like bird, is much beloved by today’s Hokies.  Since the last makeover in 1987, the Hokie Bird has maintained a consistent look.  You can follow the Hokie bird mascot @TheHokieBird on Twitter along with 16,700 other followers! The purpose of a mascot is to inspire fans.  If a mascot is working, then there is no reason to change. But the mascot changed once, it could happen again.  Couldn’t it?  The Hokie Bird is very busy and Virginia Tech is expanding; perhaps a Hokie Fish would be a welcome helper.

 

Virginia Tech's Hokie Bird mascot.  Source

But what fish would have wide appeal?  Is there a Hokie fish?  Few colleges have fish as mascots.  There the Palm Beach Atlantic University Sailfish, Muskegum Muskies, University of Virginia Wahoos, and the Fighting Salmon.   If Virginia Tech selected a fish, would it be Brook Trout, Blacknose Dace, Bluehead Chub, Walleye, or Flathead Catfish?   Each of these fish has strong local connections to habitats.  The Brook Trout is the icon of high elevation Appalachian mountain streams.  Blacknose Dace is more widespread, occurring in small streams from the mountains to the urban streams; it should be the official fish of Blacksburg since it dominates in Stroubles Creek and tributaries.  The Bluehead Chub is another local favorite due to its macho head tubercles and gravel-mound building habits.  "Chubby" appears on Blacksburg parade floats since 2015.  The Walleye is a terrific food and sport fish and a unique river-spawning form exists in the upper New River.  But if you want a big, tough mascot I suggest you pick the Flathead Catfish, a large fish-eating catfish that grows as large as a VW (No, not quite.).  

There is a fish named the Hoki. At least at the fish market, the Blue Grenadier Macruronus novaezelandiae (Hector 1871) is referred to as the Hoki.  Is the Hoki fishery cutting it? Would it be a worthy mascot?  The Blue Grenadier, is a member of the merluccid hakes (Merlucciidae) in the order of cods (Gadiformes).  

 

Blue Grenadier Macruronus novaezelandiae (Hector 1871) or Hoki. Source.

The Blue Grenadier (aka Hoki ) schools in the mesopelagic zone in waters from 200-700 m deep.  The body form is very elongate and compressed with a tapering tail, dorsal and anal fins confluent with the caudal fin.  It is a visual predator with large eyes.   The long body provides for a long lateral line and that distant touch sense.   It might be a challenge to develop an anthropomorphic Hoki Fish design.  It certainly is no Charlie the Tuna.  

The Hoki’s habitat, the mesopelagic zone, is a difficult environment even for a fish.   To begin with there is insufficient light for photosynthesis. So consumers must rely on poop or detritus from the epipelagic zone, or they must expend limited energy reserves to migrate up into epipelagic zone to find food and do this at night to avoid predators. Second, it's cold, very cold, only 4-8°C.  Oxygen levels at these depths are at minimal levels, so metabolism is slow and, perhaps, life is boring for the Hoki.  The Hoki must grow to 65-70 cm to reach sexual maturity; it takes 4-7 years.  The Hoki can reach 120 cm and 1.5 kg, but that may take a long time, up to 25 years!

With it's large toothy mouth, the Hoki feeds on a variety of small fishes, especially lanternfishes (family Myctophidae), crustaceans such as prawns, euphausiids, galatheids, and squids (Bulman and Blaber 1986; Brickle et al. 2009; Connell et al. 2010)

Common diet items of the Hoki.  Top row: Natant decapods, Squat Lobster (Galatheidae), Shrimp (Pasiphaeidae), and Krill (Ephausiidae)   Second row: Marine Hatchetfish (Sternoptychidae),  Slender Lanternfish (Gonichthys barnesi),  Thorntooth Grenadier (Lepidorhynchus denticulatus) Third row: Silver lighthouse fish (Photichthys argenteus), squid (Lycoteuthis lorigera)

The Hoki must move up in the water column to feed at night. Vertical migration is an adaptation of many mesopelagic fish and invertebrates (Watanabe et al. 1999). These vertical migrations often occur over a large vertical distance with the aid of a physoclistous swim bladder.  They appear to follow migrations of other mesopelagic fish prey.  McClatchie et al. (2005) found that "catch rate of hoki was correlated with the abundance of vertically migrating mesopelagic fish.”  One would think these fish would be safe from humans.  But we humans love our fish nuggets and fish sticks, so even deepwater fish are harvested.

The Hoki is one of the most valuable New Zealand fisheries, where catches since 1987 ranged between between 200,000 and 250,000 tonnes (Coombs and Cordue 1995). It is also an important commercial fish off Victoria and Tasmania in Australia. Much of the fish in the McDonald's Fillet-O-Fish Burger sold in Australia (and all of it in New Zealand) is the Hoki.     McDonald’s in North America used to use the Hoki, but stopped using Hoki in 2013 in favor of Alaskan pollock. Another species of Hoki is harvested off Argentina.  The Argentine Hoki (Macruronus magellanicus) fishery received Marine Stewardship Council (MSC) certification in May 2012. 

Hoki are caught using bottom and midwater trawl gear towed from large trawlers. Travel to New Zealand and watch a Hoki trawler in action.  Is the Hoki fishery sustainable?  There are problems with this fishery.  Bycatch of seals and seabirds  (albatrosses and petrels) is a major problem.  The seals and seabirds are attracted to fishing vessels as an opportunistic source of food.  "The New Zealand fishery kill 200-300 fur seals per year. The Australian fishery is limited to 30 seal deaths per year. Both fisheries are implementing seal exclusion devices to reduce seal bycatch.   Seabird bycatch is more difficult to reduce. 

After the Hoki fishery was first certified in 2001, the Royal Forest and Bird Protection Society of New Zealand filed an objection with MSC and requested that certification be withdrawn.  By 2007, several conditions were placed on the fishery with regard to seabird bycatch and by 2010 the Hoki fishery was not killing a lot of seabirds (Deepwater Group Limited 2011; Wiedenfeld 2012).   

The Marine Stewardship Council, is a non-profit organization that certifies fisheries sustainability based on three principles, namely (1) Sustainable fish stocks; (2) Minimizing environmental impact; and (3) Effective management (Marine Stewardship Council 2010).  Each fishery is scored based on 31 performance indicators.  Fisheries that want the certification pay US$20,000 to more than $100,000 to an independent, for-profit contractor that assesses the fishery against the MSC standards and determines whether to recommend certification.   Is this an automatic conflict of interest based on a self-serving free market entity? Or is it a viable free market solution for sustainable solution (Jacquet et al. 2010)?  At the moment, the MSC is the dominant organization certifying sustainability for wild-capture fisheries for sale at markets, such as Whole Foods Market.   Alternatives, such as The Safina Center’s Sustainable Seafood program, do exist.

Hoki Spawning stock biomass trajectories approach the sustainability target of 35-50% of long-term spawning biomass in absence of fishing.  DeepWater Group Limited 2011.

While the Hoki is a large and important commercial fish and its fishery is working towards sustainability goals, I don't think I can generate enthusiasm for naming a Hoki Fish as a new or additional Virginia Tech mascot. The "You're not from around here" sentiment may be too strong.   The Hokie Bird is wildly popular and one of the proud VT traditions. Plus the Hokie Bird reminds us of the eastern Wild Turkey conservation success story.   So it turns out that David Luther is wrong; Hokie Bird is not a dumb mascot.   But the idea of a Hokie Fish mascot is one that needs further work.  If you have a good fish to nominate, please comment here. 

References

Bulman, C.M., and S.J.M. Blaber.1986. Feeding ecology of Macruronus novaezealandiae (Hector) (Teleostei : Merluciidae) in south-eastern Australia. Australian Journal of Marine and Freshwater Research 37: 621-639

Connell, A.M., M.R. Dunn, and J. Forman. 2010. Diet and dietary variation of New Zealand hoki Macruronus novaezelandiae.   New Zealand Journal of Marine and Freshwater Research  44(4):289-308.

Coombs, R.F., and P.L. Cordue. 1995. Evolution of a stock assessment tool: acoustic surveys of spawning hoki () off the west coast of South Island, New Zealand, 1985–1991. New Zealand Journal of Marine and Freshwater Research 29: 175–194.

DeepWater Group Limited.  2011.  Sustainable management of New Zealand’s Hoki fisheries      

Jacquet, J. D., D. Pauly, S. Ainley, S. Holt, P. Dayton, and J. Jackson.  2010. Seafood stewardship in crisis. Nature 467 (7311): 28–29. doi:10.1038/467028a

Marine Stewardship Council. 2010.  Principles and Criteria for Sustainable Fishing.    available at http://go.nature.com/UT46uo

McClatchie, S., M. Pinkerton, and M.E. Livingston, 2005. Relating the distribution of a semi-demersal fish, Macruronus novaezelandiae, to their pelagic food supply. Deep-sea Research I: Oceanographic Research Papers 52:1489–1501.

http://www.sciencedirect.com/science/article/pii/S0967063705000646

Watanabe, H., M. Moku, K. Kawaguchi, K. Ishimaru, and A. Ohno. 1999. Diel vertical migration of myctophid fishes (Family Myctophidae) in the transitional waters of the western North Pacific. Fisheries Oceanography 8(2):115-127

Wiedenfeld, D.A. 2012. Analysis of the effects of Marine Stewardship Council fishery certification on the conservation of seabirds.  American Bird Conservancy.  The Plains, Virginia.  40 pp.