Aquatic Pollution and Coastal Management

Unit 11 : Monitoring and control of pollution

11.10.2.Finfish
Advantages

• Fish are good indicators of long-term effects (several years) and habitat conditions.
• Fish communities represent a variety of trophic levels; toxic substances tend to biomagnify and thus the fish community structure reflects community health.
• Fish are consumed by humans.
• Fish are relatively easy to collect and identify.
• Environmental requirements, life history information and distribution are well known for most species.

Disadvantages

• Motility and migration cause difficulty in pinpointing a pollutant as the cause of abnormalities in individuals or a population.
• Monitoring only certain fish species will miss changes in the benthic community or in other species in the community that over time will affect the fish species.
• Fish are not as sensitive as their food (macroinvertebrates) to pollution and monitoring of fish may not reflect severe changes in the invertebrate community.
• An assessment of fish alone will not ensure "ecosystem health".

Example indicator fish species by impairment type
Oxygen depletion Darter species salmonids sculpin species benthic insectivores Sedimentation Darter species Salmonids Sculpin species Benthic insectivores Degradation of pools and vegetative cover Sunfish species (centrarchids) Minnow species (cyprinids) salmonids Physical and chemical degradation of the water resource (long lived species) Suckers (catostomids) adult trout minnows catfish Tolerant species - distinguish low from moderately degraded waters Green sunfish common carp White sucker bullhead creek chub dace Trophic level tolerance (overall) used for the Index of biotic Integrity omnivores carp tolerant white sucker tolerant bullhead minnow intermediate fathead minnow tolerant yearlings Insectivores Insectivorous cyprinids intolerant to intermediate Juvenile trout intolerant cutthroat trout intolerant Rainbow trout intolerant brook trout intermediate White crappie intermediate paiute sculpin intolerant torrent Sculpin intolerant Prickly sculpin intermediate reticulate sculpin tolerant madtom intolerant carnivores salmon intermediate bass intermediate Pike intermediate walleye intermediate yellow perch intermediate lake trout intermediate