This week Weekly Water Watch looks how nutrient pollution impacts aquatic species, which can rob fishing of its fun. Threats to Fish Populations Algae in the water can make it hard for fish to survive. According to the EPA, “too much nitrogen and phosphorus in the water causes algae. Algal blooms…can severely reduce or eliminate oxygen in the water, leading to illnesses in fish and the death of large numbers of fish.” A mass die-off is called a fish kill, which can be caused by algae, but also by other environmental factors such as disease or sudden temperature change, or by human-related factors, such as manure releases or fertilizer applications. Fish kills are occasionally reported in Iowa. One fish kill has been reported so far in 2019, due to manure runoff in a tributary of the Little Maquoketa River in Dubuque County. Poor Fishing Conditions Algae blooms float on top of the water, leading to an unappealing and sometimes smelly visit to a fishing hole. When the bloom is active, it can be unsafe to maneuver a boat or other water vessel, not to mention hard to identify where fish are active in the water. When the algae dies, the resulting smell of decay can make you look for a different activity other than fishing! Safe to Eat? Fish and shellfish can be contaminated by toxins from Harmful Algal Blooms (HABs), and cause human illness or death if consumed. HABs can also damage or clog fish gills, or block sunlight for beneficial algae. Most fish caught in Iowa lakes and streams are safe to eat, but the DNR does provide an annual report of consumption advisories. This report does not include acute hazards, such as microcystin or other toxins produced by HABs. A recent piece in the Des Moines Register chronicled fish monitoring methods in Iowa and around the Midwest. Clean Water is the Key Ensuring Iowa has clean water also ensures one of the most popular outdoor sporting activities remains available for future generations. Help IEC make the call for clean water in Iowa – support our work today! And don't forget to check IEC's Water Watch each week to check for beach advisories, including bacteria and microcystin. Enjoy Iowa's waters with some fishing this weekend! - Alicia Vasto, IEC Water Policy and Advocacy Specialist PS - You're receiving this email because you've shown an interest in IEC's work. To continue receiving the Weekly Water Watch, please subscribe to the newsletter list. | 
