Lake Michigan's fish population collapsed in 2187. The collapse was not sudden — it was the culmination of two centuries of industrial contamination, thermal pollution from power generation, invasive species proliferation, and the cumulative effect of geneware runoff from the metropolitan zones that ring the lake's southern shore. By 2187, commercial fishing yields had declined to less than 4% of 2050 levels. The lake was, in the assessment of GLMZ Aquatic Biology, "functionally depauperate" — alive, but barely. The fishing communities of Old Harbor, which had sustained themselves on lake fish for generations, turned to aquaculture and printed protein. The lake was written off.

It came back. Between 2195 and 2210, fish populations in the southern basin of Lake Michigan recovered to approximately 60% of pre-collapse biomass. The recovery was rapid, unexpected, and — from a taxonomic standpoint — deeply confusing. The species that returned were not the species that had declined. Lake trout, walleye, perch, and whitefish — the historical species assemblage — did not recover. Instead, the lake filled with organisms that do not match any species in the Great Lakes biological record. They are fish. They have fins, scales, gills, and the general morphology of freshwater teleosts. But they are not any fish that has existed before.

Genetic analysis conducted by the GLMZ Aquatic Biology Division over the period 2210–2224 has produced results that the division's lead geneticist, Dr. Amara Nwosu-Lindqvist, describes as "creative." The new fish appear to be hybrids of multiple native species — combinations that are reproductively impossible under normal biological conditions. Specimens have been identified with genetic material from lake trout and smallmouth bass, from walleye and alewife, from species that occupy different ecological niches and could not naturally interbreed. The hybridization events appear to have been mediated by geneware agents in the lake water — gene transfer vectors originally designed for human therapeutic applications that, in the lake's contaminated environment, acted as indiscriminate genetic shufflers, combining available genetic material into novel configurations.

The fish taste fine. The Old Harbor fishing cooperative resumed commercial operations in 2212, initially with considerable trepidation. Toxicological testing of the new species found no harmful compounds at concentrations exceeding safety thresholds. Nutritional profiles are comparable to historical lake fish. The flesh is firm, mildly flavored, and takes well to smoking. Old Harbor sells fresh and smoked fish at the Circuit night market under the brand name "New Catch." The packaging does not mention the genetic anomalies. The customers do not ask.

The question that the Aquatic Biology Division cannot answer is whether the new species are stable. Fifteen years of monitoring suggests they are breeding true — offspring resemble parents, populations are self-sustaining, ecological niches are being filled. But the geneware agents that created them are still in the water. New combinations continue to appear. Last year, a fisherman in Old Harbor pulled up a specimen with bioluminescent lateral lines and what appeared to be rudimentary electric organs — structures found in no freshwater fish native to North America. The specimen was delivered to the division for analysis. The results are pending. The fisherman says it tasted like walleye.