The National Park Service Pacific Island Network Inventory & Monitoring Program began monitoring marine benthic (seafloor) and marine fish communities at Kalaupapa National Historical Park (KALA) and Kaloko-Honokōhau National Historical Park (KAHO) in 2006 and 2007, respectively. Results from these efforts have indicated that KALA has a more substantial fish assemblage in terms of biomass (total fish weight) compared to what has been observed at KAHO (Figure 1). At the same time coral cover at KAHO is substantially higher with less algal cover than what is seen at KALA (Figure 2).
The unique marine assemblages at these coastal parks provide an excellent opportunity to study nutrient inputs into nearshore waters, and its influence on benthic communities and the associated fish assemblage. Damaging algal blooms, a growing problem for Hawaii’s coral reefs, have been linked to man-made nutrient inputs from land. As coastal land-use and nutrient inputs increase over time, grazing by fish, urchins, and turtles may naturally control algal growth and stem reef decline. These results and potential controlling factors have stimulated research questions such as:
- What factors help explain why KALA has higher algal cover AND higher fish biomass, particularly herbivore biomass, which should theoretically keep the algae in check?
- Would the larger human population adjacent to KAHO result in higher nutrients within park waters?