Final answer:
The experimental removal of cleaner fish in portions of the Great Barrier Reef has demonstrated the importance of positive interactions for maintaining species abundance and overall marine ecosystem health, highlighting the complex dynamics and biotic resistance within coral reefs.
Step-by-step explanation:
The removal of cleaner fish from patches of reef within the Great Barrier Reef has shown that positive interactions can significantly affect species abundance. Cleaner fish, by feeding on parasites and dead tissue from other fish species, contribute to the health of marine ecosystems. Their absence can lead to a decrease in abundance and diversity, further indicating how interdependent species within an ecosystem are. Furthermore, as the study suggests, interactions such as these are pivotal in maintaining the complex dynamics of coral reefs, which are home to a large proportion of marine species despite covering a small area of the marine habitat. Biotic resistance, where native diversity can limit the effects of invasive species, also demonstrates the importance of maintaining species abundance and diversity for ecosystem health.