Understanding the importance of habitat complexity for juvenile fish and the application of 3D printed corals for reef restoration
Date
2018
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Publisher
University of Delaware
Abstract
Coral reef systems have been experiencing ongoing regional declines in important topographic and biotic complexity over the last 40 years. While studies have documented the importance of live coral cover in the habitat selection process of reef fishes, the role that habitat complexity plays in these choices is poorly understood. Here, we isolated the physical structure of a common Indo-Pacific reef building coral, Pocillopora damicornis, using 3D printed models to investigate complexity preferences and resulting behavior of the coral-associated lemon damselfish, Pomacentrus moluccensis. A secondary objective of this work was to determine if 3D printed objects could be used in reef restoration by providing critical habitat for fishes and acting as viable settlement sites for recruiting reef-building corals. During a cafeteria-style choice experiment, P. moluccensis was highly selective of the high and medium complexity corals over the low complexity coral. During behavioral observations, fish occupying 3D printed low complexity corals had the highest rate of abandonment and most deviant behavior from live and dead control P. damicornis coral heads. Conversely, fish placed on 3D printed medium and high complexity corals spent more time utilizing the shelter than fish on control corals and behaved similarly to the controls when not utilizing the shelter. These results show that coral physical structure is an important factor driving habitat preferences of P. moluccensis and plays a critical role in influencing their behavior. Further, coral settlement was observed using 3D printed settlement tiles made of different filaments placed on a Fijian reef. Coral settlement was highest on nGen material. Thus, artificial corals made using 3D printing technology designed to mimic the structural complexity of healthy reefs have the potential to be used as reef habitat restoration structures in the future.
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Keywords
Biological sciences, 3D print, Behavior, Coral, Damselfish, Ecology