Inland lakes fisheries: water quality, fish abundance and economic value

Recreational fishing is a valuable ecosystem service of inland lakes which is dependent upon provisioning services supporting fisheries production. Nutrient pollution degrades these provisioning services and adversely affects... [ view full abstract ]

Recreational fishing is a valuable ecosystem service of inland lakes which is dependent upon provisioning services supporting fisheries production. Nutrient pollution degrades these provisioning services and adversely affects fisheries, yet reducing loadings from non-point sources such as agriculture has historically been challenging and is likely to remain so in the future. Understanding the benefits of reduced pollution can improve decision making.  Yet, deriving the benefits of reduced nutrient loadings requires an integrated understanding of how ecosystem service values depend on loadings. Ecological production functions were estimated relating fish abundance to phosphorus loadings in Michigan. These species-specific spatial abundance models were linked to recreation fishing demand. The demand model uses data on fishing locations collected via monthly mail surveys that have been occurring since 2008. The demand model relates angler behaviors (species sought, number of trips, and fishing locations) to distances and abundance of fish at sites. Previous efforts with this data have established the demand and value for river fishing, and this research extends the models so fishing sites include 1610 individual Michigan lakes over 10 acres. The resulting integrated spatial models linking phosphorous loading to fishing behaviors inform economic estimates of fishing benefits resulting from water quality improvements due to reduced nutrient loads, and provide predictions of how patterns of fishing across the landscape would change in response to reduced nutrient loads, which can inform future efforts to manage fisheries and facilitate policies reducing non-point source pollution.