Chapter 3.27
3.27. Oyster
Kevin Johnston , University of Guelph, Canada
Suggested citation for this chapter.
Johnston,K. (2022) Fish And Freshwater/Marine Invertebrates. In The Student Encyclopedia of Canadian Indigenous Foods. Editor, M.N. Raizada, University of Guelph, Canada. http://www.firstnationsfoods.org/
Introduction
Oysters are a type of bivalve shellfish: a commonly found delicacy in most open waters around the world (Bayne, 2017)They are renowned for their sophisticated taste and impacts on the aquaculture industry (Chigale, n.d.). The purpose of this report is to bring more awareness to indigenous communities about oysters and offer insight surrounding the potentiality of oyster farming from an industry standpoint.
Biology And Ethnology
The term oyster covers the entire genius of the superfamily Ostreoidea (Bayne, 2017). These are different salt-water bivalve molluscs that inhabit brackish or marine conditions (Bayne, 2017). This includes true oysters, pearl oysters, thorny oysters, scallops, etc (Bayne, 2017). However, for the entirety of this paper the term “oyster” will be used to classify only “true oysters” unless explicitly stated otherwise. True oysters are the kind that people eat and these belong to the genius Ostreoida (Bayne, 2017). Other commonly used names for them are flat and rock oysters (Bayne, 2017)
The exact number of classifications for all oysters has always been somewhat complicated and unreliable (Bayne, 2017). This is largely due to the extreme similarities between the different species because of their lengthy biological history (Kocher & Kole, 2008). All known oysters have 10 chromosomes of which very little is known (Kocher & Kole, 2008). This quantity is much fewer in comparison to other crustations like clams and scallops which have 19 chromosomes (Kocher & Kole, 2008). The main theory for the reduced value of chromosomes compared to other crustations is that oysters derive from ancient tetraploids (Kocher & Kole, 2008). As a result of this biological divergence, 40 to 60 separate species of oysters exist and are classified (Kocher & Kole, 2008).
Oysters are an integral part of any ecosystem they are a part of and are known to be a keystone species and/or ecological engineers (Bayne, 2017). The reason for this appraised title is regarding their shell. What’s very notable about the oyster is their shells and shell fragments which are durable and last for long periods of time (Bayne, 2017). It has been observed that many oysters are “reef building” and that their dead carcasses are melded into the reef matrix (Bayne, 2017). They also play an important role in ocean floor ecosystems (Bayne, 2017). They introduce complexity, where they influence population level and ecosystem level processes as well as produce large amounts of calcium for microscopic species (Bayne, 2017). They are also natural provisioners attributed for water filtration (Bayne, 2017).
An oyster’s diet mostly consists of floating nutrients in the water (Rajapandian & Rajan, 1987). Due to their limited movement, the food particles must be carried by the water in order to get trapped within the gills (Rajapandian & Rajan, 1987). Oysters rely solely on this method of food for their entire lives (Rajapandian & Rajan, 1987). They tend to grow to about 86.7 mm in size, maintaining the same ratio of body size to shell size as their shell grows at approximately the same rate (Rajapandian & Rajan, 1987). Most of this growth is over the first three months of their lives with the pace of growth slowing over time until 1 year when they reach full size (Rajapandian & Rajan, 1987). This is also around the time where they reach sexual maturity (Rajapandian & Rajan, 1987). When oysters reproduce, they can produce millions of eggs that will float in the water and digest material like grown oysters (Rajapandian & Rajan, 1987). It has also been noted that oysters are able to change their sex to suit their anatomical needs (Rajapandian & Rajan, 1987).
Historical And Cultrual Background
Traditional indigenous knowledge is evolved-knowledge that has been passed down through generations of living symbiotically with the environment (Chigale, n.d.). It is the ultimate form of environmental value and helps cement the people’s way of life (Chigale, n.d.). Hunting and fishing are among the oldest forms of human activity and most of the required knowledge is attributed to the first nations (Chigale, n.d.).
For Canadian indigenous peoples, oysters were first incorporated into the diets of coastal communities (Moss, 1993). Virtually all indigenous costal groups collected and ate some form of shellfish (Moss, 1993). Algonquian peoples tended to call oyster “e’sis,” which has become a common name to describe most bivalves (Kuhnlein & Humphries, 2017). For a lot of indigenous peoples, oysters where staple to get enough protein and an essential part of their diet (Erlandson, 1988). In some circumstances it would be more efficient to farm oysters, or another type of shellfish as opposed to terrestrial alternatives (Erlandson, 1988). Oysters were typically obtained from beaches where they were dug up and stored in bark baskets (Kuhnlein & Humphries, 2017). Some western communities would gather oyster clusters around rocks on the beach; where they were most plentiful because they would get stuck and collect when the tide would come up (Kuhnlein & Humphries, 2017). The act of collecting was often a challenge as oysters are not uniformly distributed or accessible through out their habitat (Moss, 1993). There was a need for low tides and new or full moons (Moss, 1993). Moreover, Habitat requirements, tidal positions, size, and density also severely fluctuated the degree of oyster gathering and by extension economic reliance (Moss, 1993). In leu of this, a proposition in Millington Horizon shows the possible functionality and success of oyster cultivation (Erlandson, 1988). With a very small bar regarding technology requirements (especially when regarding other types of hunting) and low population for exploiting the land, while also being very feasible (Erlandson, 1988). They were reported to have up to 90 percent of their protean intake deriving from shellfish (Erlandson, 1988). Oyster farming also comes with ample economic prospects (Moss, 1993). Not only is the shell a source of raw material for a variety of functional tools, but the flesh is used for fishing bait and in tobacco chewing (Moss, 1993).
Oyster cultivation was traditionally handled by women and rarely, if ever did the husbands help (Moss, 1993). Northwestern coastal cultures tended to avoid oysters during summer months because of the prevalence of shellfish poising due to warmer temperatures allowing harmful bacteria to thrive (Kuhnlein & Humphries, 2017). Over time many species became too hard and rough for consumption, hindering indigenous people from having a diet supported by oysters. (Moss, 1993). This is something that can be read further under the “LIMITATIONS.” section The Wampanoag peoples would store large numbers of oysters for winter even though there was an abundance (Kuhnlein & Humphries, 2017). However, in recent years, oysters are becoming harder to find and gather (Kuhnlein & Humphries, 2017). Pacific Coast first nations had fewer estuaries along the Atlantic but had a greater density of oysters (Reeder-Myers et al., 2022). However much like the Wampanoag there became a trend varying the degree of abundancy for oysters (Reeder-Myers et al., 2022). The biggest culprit of this decrease is climate change and modern influence exploiting the industry (Reeder-Myers et al., 2022).
Geographical Origin
Oysters are global, costal creatures residing typically in shallow zones of estuaries, marshes, and bays (Bayne, 2017). Locally, they are found in clusters on sedimentary/shelly sea bottoms or associated with the roots of mangrove trees (Bayne, 2017). Unique to oysters is that their distribution is not even nor random, but rather patches of high abundance. (Bayne, 2017) Specifically in Canada, two species exist: the Eastern oyster and the Olympic oyster (Kuhnlein & Humphries, 2017). The two occupy the east and west coast of Canada respectively (Kuhnlein & Humphries, 2017). Though both are common, the pacific oyster originating from Japan is the primarily used oyster in the aquaculture industry (Government of Canada, 2017).
Associated Indegenous Peoples
First nations peoples who live in coastal regions of North America have strived for a long-standing relationship with oyster harvesting (Lavoie, 2009). Communities like the Lummi First Nation and Squamish Indian Tribe have operated shellfish hatcheries since the 70’s (Lavoie, 2009). In Canada, first nations people have created a group known as the Aboriginal Aquaculture Association to aid in the development of first nations aquaculture including the collection of oysters (Lavoie, 2009). Historically Canadian communities like Twana of Puget Sound, Coast Salish, Nootka on the northwest coast and Penobscot, Iroquois, and Wampanoag on the northeast coast were known to have a prevalent connection with oysters (Kuhnlein & Humphries, 2017). However due to numerous circumstances and limitations many indigenous communities are having to veer off oyster consumption (Reeder-Myers et al., 2022). The association of indigenous peoples with oysters transcends just Canada and North America (Reeder-Myers et al., 2022). Peoples from different costal parts of the world like Mexico, Australia, and India also consume and rely on oysters as a part of their diet (Reeder-Myers et al., 2022).
Oysters hold great importance to coastal culture and dining worldwide (Reeder-Myers et al., 2022). Seri in Sonora would collect oyster from offshore reefs (Reeder-Myers et al., 2022). In Queensland Australia, oysters could make up to 95 percent of their shellfish consumption (Reeder-Myers et al., 2022). Early peoples travel to islands by canoes in order to harvest oysters (Reeder-Myers et al., 2022). They are often harvested at low tides with spears and collected with dilly bags (Reeder-Myers et al., 2022). These techniques have been passed down through generations and is the reason why the hunting season is consequently longer for First Nations peoples (Reeder-Myers et al., 2022).
Consumption And Uses
Oysters would usually be boiled or steamed in order to soften them, similarly to how mussels are prepared (Kuhnlein & Humphries, 2017). It is uncommon to see them consumed raw, but some communities occasionally practice this (Kuhnlein & Humphries, 2017). Interestingly, the Manhousat steam their oysters and drink the broth as a tea (Kuhnlein & Humphries, 2017). It is thought that this increases male potency during reproduction (Kuhnlein & Humphries, 2017). Not only are oysters important food elements but they are also used in social, political, and economic fashions (Eoin, 2022).. These uses range widely from ancestral burial mounds to water control features (Eoin, 2022). They also held many practical uses in the construction of hand made tools (Moss, 1993). People could craft hunting weapons like knives and harpoon heads with them or use the shells for cooking as spoons or ladles (Moss, 1993).
Health Benefits
Shellfish have extremely beneficial qualities for consumption (Venugopal & Gopakumar, 2017). They are rich in vitamins and minerals like copper and zinc (Venugopal & Gopakumar, 2017). Oysters are also filled with essential amino acids that are critical for human function (Venugopal & Gopakumar, 2017). These protein engines are also sometime very dangerous for humans to eat (Venugopal & Gopakumar, 2017). Though it is uncommon, oysters can have very high levels of environmental pollutants, pathogenic organisms and other unwanted chemicals or toxins (Venugopal & Gopakumar, 2017). The reason for this is due to the filter-feeding nature of oysters (Venugopal & Gopakumar, 2017). Oysters sit in the water and consume what ever flows through them, that includes harmful toxins (Venugopal & Gopakumar, 2017). Obviously, this is unwanted and negatively affects human life (Venugopal & Gopakumar, 2017). However, because of this property, the sight of thriving oysters suggests clean water that is safe to be around (Venugopal & Gopakumar, 2017).
Limitaions
A theme is starting to develop regarding the sustainability of oyster consumption. Overharvesting, pollution, habitat loss, and competition from invasive species is increasing the difficulty for feasible oyster farming. (Eoin, 2022) Sea levels in northern Canada are also particularly problematic due to the proximity of the continental ice sheets (Reeder-Myers et al., 2022). Sea level stabilization is critical for estuaries, which are the habitats for many oyster species (Reeder-Myers et al., 2022). Prominence of disease is rising in all types of shellfish and very recently studies have found a rise of cadmium: a toxic metal in oysters (Bendell, 2010). This has brought up pandemonium, specifically for the BC shellfish industry as consumers are now fearful of these conditions (Bendell, 2010). This is because oysters are filter-feeders, thus absorb viral agents and pollutants in the water (Kuhnlein & Humphries, 2017). These crippling qualities make it hard to incorporate oyster into the diets and lives of modern-day indigenous peoples unlike their ancestors.
References
1.Bendell, L. I. (2010). Cadmium in shellfish: The British Columbia, Canada experience—a mini-review. Toxicology Letters, 198(1), 7–12. https://doi.org/10.1016/j.toxlet.2010.04.012
2.Bayne, B. (2017). Biology of oysters. Academic Press.
3.Chogale, N. D., Nirmale, V. H., Metar, S. Y., Gangan, S. S., Pai, R., Pawar, R. A., & Singh, H. (2018, January 1). Assessment of indigenous knowledge on edibility of oyster, crassostrea madrasensis from the ratnagiri coast of Maharashtra. NOPR. Retrieved November 17, 2022, from http://nopr.niscpr.res.in/handle/123456789/43130
4.Erlandson, J. M. (1988). The role of shellfish in prehistoric economies: A protein perspective. American Antiquity, 53(1), 102–109. https://doi.org/10.2307/281156
5.Government of Canada, F. and O. C. (2017, March 15). Government of Canada. Government of Canada, Fisheries and Oceans Canada, Communications Branch. Retrieved November 16, 2022, from https://www.dfo-mpo.gc.ca/aquaculture/sector-secteur/species-especes/oysters-huitres-eng.htm
6.Kocher, T., & Kole, C. (2008). Genome mapping and genomics in fishes and aquatic animals. Springer Berlin Heidelberg.
7.Kuhnlein, H.V. and Humphries, M. M. 2017. Traditional Animal Foods of Indigenous Peoples of Northern North America: Centre for Indigenous Peoples’ Nutrition and Environment, McGill University, Montreal. http://traditionalanimalfoods.org/.
8.Lavoie, R. E. (2005). Oyster culture in North America: history, present and future. In The 1st International Oyster Symposium Proceedings. Tokyo, Japan (pp. 14-19).
9.Moss, M. L. (1993). Shellfish, gender, and status on the Northwest Coast: Reconciling Archeological, ethnographic, and ethnohistorical records of the Tlingit. American Anthropologist, 95(3), 631–652. https://doi.org/10.1525/aa.1993.95.3.02a00050
10.Nic Eoin, L. (2022). Healthy indigenous harvests. Nature Ecology & Evolution, 6(7), 842–842. https://doi.org/10.1038/s41559-022-01785-0
11.Reeder-Myers, L., Braje, T. J., Hofman, C. A., Elliott Smith, E. A., Garland, C. J., Grone, M., Hadden, C. S., Hatch, M., Hunt, T., Kelley, A., LeFebvre, M. J., Lockman, M., McKechnie, I., McNiven, I. J., Newsom, B., Pluckhahn, T., Sanchez, G., Schwadron, M., Smith, K. Y., … Rick, T. C. (2022). Indigenous oyster fisheries persisted for millennia and should inform future management. Nature Communications, 13(1). https://doi.org/10.1038/s41467-022-29818-z
12.Rajapandian, M E and Rajan, C T (1987) Biological aspects of oysters. CMFRI Bulletin, 38. pp. 30-29.
13.Venugopal, V., & Gopakumar, K. (2017). Shellfish: Nutritive value, health benefits, and Consumer Safety. Comprehensive Reviews in Food Science and Food Safety, 16(6), 1219–1242. https://doi.org/10.1111/1541-4337.12312