Zooplankton assemblage and body size responses to severe lake eutrophication from agricultural activities near mink farms in Nova Scotia, Canada

Abstract

Mink fur farming was once a widespread agricultural activity in southwestern Nova Scotia. Freshwaters near to and downstream of several mink fur farm operations have experienced severe water quality issues, including eutrophication and recurring algal blooms. Here, we use dated lake sediments to examine trends in primary producers and primary consumers from a hypereutrophic lake to assess how cladoceran assemblages have responded to extreme eutrophication. Shifts in the dominant pelagic cladoceran taxa began in the early 1900s, coinciding with an increase in sedimentary chlorophyll-a concentrations. Notably, small-bodied bosminids decreased, while taxa such as Chydorus brevilabris and Daphnia pulex spp. dominated assemblages in recent decades. Bottom-up ecological factors, such as decades of greater primary production, were the likely drivers of assemblage shifts of primary consumers. Consistent body sizes of bosminids throughout the sedimentary record suggested that pelagic cladocerans were not influenced solely by predation pressure from macroinvertebrates or fish. This study provides evidence of large-scale ecological shifts occurring at multiple trophic levels in a hypereutrophic temperate lake with mink farming operations in its catchment.

One health implications of fur farming

“…( Van Heyst et al, 2022) Reported the severe eutrophication of lake downstream from mink farm causing changes in zooplankton assemblages. (Jones et al, 2022) Constructed a nitrogen loading model, showing that contributions from fur farming and seafood processing disproportionately affected smaller water bodies rather than larger ones. Where water turnover is low or in small water bodies localised industry such as fur farming and be a significant cause of eutrophication.…”

Eutrophication of Water Body Based on Ecological Simulation Technology

“…Ecological floating bed, also known as artificial floating bed, biological floating bed, ecological floating bed, plant filter bed, soilless cultivation floating bed, etc., is a device that plants higher aquatic plants or terrestrial water loving plants after adaptive cultivation on the carrier, forms an efficient artificial ecosystem through absorption, adsorption and integration of plants and microorganisms, inhibits the growth of algae in the water body, and creates a water landscape [12].…”

Congruence of water column, contemporary and pre‐industrial sediment cladoceran assemblages in 85 Canadian lakes of contrasting human impact levels

“…Changes in zooplankton composition or diversity can thus occur after the arrival of a new stressor and can be interpreted as an early‐warning sign of ecosystem perturbation (Patalas et al., 1994). For example, changes to farming practices and increases in industrial agriculture have affected the trophic state of many lakes, with demonstrable effects on zooplankton communities (Albert et al., 2010; Jones et al., 2022; Paquette, Gregory‐Eaves, & Beisner, 2022).…”