Environmental Concerns

El Niño:

High energy storms or swells can uproot entire plants and break away the fronds of kelp. Characterized by severe storms and warm water, El Niño Southern Oscillation Events, often devastate kelp forests. The strong swell activity, winter storms, and warm weather associated with the 1997-1998 El Niño were the primary sources of kelp mortality on the California coast in 1998. Kelp forests south of Point Coneception sustained up to 100 percent mortality in some regions, although comparable habitats north of that region were relatively unaffected. El Niño brought unusually high ocean temperatures to southern California where the heat degraded the health of the giant kelp forests. The combined warm water temperature and strong wave energy caused high mortality in the south. Central California bull kelp forests remained in cooler waters and thus in better condition when the winter swells hit, and a much greater percent survived.

Pollution:

Non-point and point source pollution including sewage, industrial disposal, and coastal runoff might contribute to kelp forest degradation. For instance, high sedimentation from coastal run-off may bury new plant shoots. Kelp may experience reduced growth rates and reproductive success in more toxic waters and sediments. Kelp is sensitive to sewage, industrial waste discharges, and other causes of poor water and sediment quality.

References

“Impacts on Kelp Forests.” National Marine Sanctuaries. October 5, 2015. http://sanctuaries.noaa.gov/visit/ecosystems/kelpimpacts.html.