Exploring Fish Introductions using GIS

A Palladio map showing bass introductions into Algonquin Park 1898-1901 along the route of the Canadian Atlantic Railway.

Scroll this

When Alfred Crosby proposed the “Columbian Exchange,” fish were notably absent from his account. One reason is that global fish exchanges are only about 150 years old. Intimately connected with nineteenth-century technologies, particularly artificial fish culture and steam-powered transportation, fish introductions lay outside Crosby’s terrestrial and temporal frame.

Environmental historians of North America have certainly recognized aquatic introductions and are showing more interest in them, for example the Global Samon Initiative. [1] But there is room for a broader accounting of fish introductions, one that captures their transnational dynamics, their varying scales and intentions, and their environmental legacies. A key question is how sport fishers (or anglers) moved fish. They didn’t just lobby governments to introduce fish, but also undertook their own game-fish introductions in parallel (and even in opposition) to fisheries managers.

Pursuing this topic, I proposed a paper on black bass introductions to British Columbia for the 2016 Canadian Historical Association’s annual meeting. I wanted to extend my research about the transplant of this eastern fresh-water species in the early 1900s to investigate how management regimes responded after sport fishers surreptitiously widened bass distribution through the twentieth century.

The paper was going to consider anglers as active, if secretive, agents of ecological change. This is a historical black box, as many anglers moved fish, often without documenting or drawing attention to their actions. I failed, however, to fully appreciate the challenges of cracking open this box, and tracking when, where, and how anglers transplanted bass around the province. My other problem was actually the potential solution to the first: using GIS (Geographic Information Systems) tools to map introductions, which sidelined my research into bass in BC in favour of GIS map-making at the opposite end of Canada.

The paper I delivered in Calgary focused on working with GIS tools, and my initial impressions of their opportunities and challenges. I related how I had been using Google Maps to map introductions, but also how I had lacked a tool to visualize vectors and thus illuminate their geographic and social connections. This became possible once I discovered Palladio, an online tool from Stanford University’s Humanities + Design Lab. Palladio is a web-based mapping and network-analysis tool: once you master the art of constructing data tables, and Palladio’s interface, you can start mapping your data.

Since I was not a master at manipulating data—nor entirely clear how Palladio worked—I followed someone who did: Miriam Posner, a media scholar who teaches digital humanities at UCLA. Miriam’s 2014 blog post, “Getting Started with Palladio,” was a godsend. Following her step-by-step instructions, and looking at her data tables, I was finally able to take some tentative steps into GIS analysis.

I began modestly, using the introduction of M. dolomieu into Algonquin Park in the late 1890s—an episode I had previously documented in my MA thesis—to test my data structuring and mapping abilities. I also tested Palladio’s ability to integrate historical maps into its visualizations. I downloaded railway-route maps of Algonquin Park and brought them into MapWarper, another free web-based app, where I ‘rectified’ or plotted them to universal coordinates. Imported into Palladio, the resulting map clearly illustrated the spatial logic of bass introductions along railways.

A Palladio map showing bass introductions into Algonquin Park 1898-1901 along the route of the Canadian Atlantic Railway.
A Palladio map showing smallmouth bass introductions into Algonquin Park 1898-1901 along the route of the Canadian Atlantic Railway.

New sources prompted more experiments. A 1949 Canadian Fish Culturist article provided data on bass introductions to New Brunswick and Nova Scotia between the 1870s and 1940s. [2] This data, compiled with that pertaining to an earlier introduction in Maine, resulted in a Palladio map that strongly suggested bass introductions to eastern Canada derived from an angler-initiated introduction from New York to Maine in 1869. [3] A superimposed map of the Maine Central Railroad showed how its extension to New Brunswick in 1871 may have been the vector for further introductions in Canada.

A Palladio map showing smallmouth bass introductions to Maine, New Brunswick, and Nova Scotia (1869-1948). The route map of the Maine Central Railroad was superimposed in Palladio.

The map also revealed how two lakes in Maine and New Brunswick—which shared a railroad and a watershed—were epicentres for further introductions, showed how introductions ramify through landscapes. Lastly, the map hinted at something obvious yet unexpected: that these fish introductions followed the historical pattern of demographic and commercial exchange between New England and eastern Canada.

These findings were exciting, but there remained the problem of determining whether introductions to New Brunswick and Nova Scotia were state-sanctioned or the result of angler intervention and/or natural colonization. That is when I started to examine contemporary distributions, hoping they could help answer these questions.

Luckily, Nova Scotia fisheries biologist Jason LeBlanc had already compiled data about the widening distribution of M. dolomieu in the province. Like biologists in other jurisdictions where bass have been introduced, he was concerned about impacts upon native species, particularly Atlantic salmon. Following Jason’s work, I turned to Google Fusion Tables to create a “heat map” of bass distribution in Nova Scotia to 2015. In Palladio, this data supported a time-series of maps. These maps, which still require analysis, show both discontinuous bass distribution (which suggest angler intervention) and continuous distribution, which points toward the agency of bass and their movements through connected lakes and rivers.

A Google Fusion Tables map showing current smallmouth bass distribution in Nova Scotia, following introductions and further naturalization between the 1940s and 2000s. Data courtesy Jason LeBlanc, Nova Scotia Fisheries and Aquaculture.

Jason’s data showed another surprising pattern, one he pointed out in conversation. While bass were introduced to Nova Scotia in the 1940s, their distribution did not appreciably widen until the 1980s, with a surge between 1990 and the present day. He suggested a correlation between bass distribution and the emergence of professional bass-fishing tournaments and cable-TV fishing shows.

This experience with GIS has been instructive. Visualizing introductions through GIS applications such as Palladio has provided me with new insights into North American fish introductions, while also leading to new questions, particularly about the entangled agencies of anglers and fish. One risk with GIS mapping is becoming too focused on specific events and ignoring bigger questions, such as the gender dynamics of introductions. Mapping should supplement and extend historical practice, rather than being an end in itself.

I will continue using Palladio and other GIS tools as I research and analyze introductions. I plan to map introductions and exchanges that occurred between Canada, Europe, Australia, and the United States. The goal is a better understanding of the history of a relatively invisible faunal redistribution, and the actors and agents who carried it out. There is also an opportunity to connect history with contemporary fisheries concerns as biologists assess the ecological impacts of fish introductions. With climate change beginning to have an significant impact upon marine and lacustrine environments, these past introductions will continue to shape fish distribution and biodiversity far into the future.

Acknowledgments: Thanks to Jason LeBlanc for sharing his data of Nova Scotia bass distribution; and to Peter Anderson, Merle Massie, and George Colpitts for organizing and participating in our CHA panel on introductions, invasions, and infections.


[1] Recent books include Jennifer C. Brown’s history of trout fisheries in the western United States (Trout Culture, 2015) and George Colpitts’ forthcoming book on southern Alberta.

[2] James Catt, “Smallmouthed black bass in the waters of New Brunswick and Nova Scotia,” The Canadian Fish Culturist 4 (1949): 15-18.

[3] G.S. Page, “Black Bass in Maine,” Transactions of American Fish-Cultural Association (Washington: 1884) 57-60. The bass for Page’s introduction, in turn, probably came from populations that had colonized lower New York by way of the Erie Canal.

The following two tabs change content below.

William Knight

Curator at Canada Science and Technology Museums Corp.
William Knight is curator of agriculture, food, and fisheries at the Canada Science and Technology Museums Corporation in Ottawa. He wrote his dissertation on the Canadian Fisheries Museum.


NiCHE encourages comments and constructive discussion of our articles. We reserve the right to delete comments that fail to meet our guidelines including comments under aliases, or that contain spam, harassment, or attacks on an individual.