Marine epibiota increase durability of rock mass breakwaters against erosion: A case study in the Gulf of Oman, Iran

The effect of marine species attached on rock mass breakwaters was evaluated on the durability of breakwaters against erosion in the Gulf of Oman, Iran. A suit of erosion indicators in rock boulders (i.e., chemical dissolution, full deterioration, roundness, exfoliation, lamination, fracture) were assessed qualitatively and visually between those materials with biota and those with no biota. The results showed that rock boulders with no biota were largely eroded than those boulders with attached biota. A significant difference was detected in all erosion indicators between rocks with attached biota and those with no biota suggesting that rocks with biota were significantly more durable against erosion than those with no biota. The conclusion from this study suggests that marine organisms attached to the rock mass breakwaters play a key role in the durability of these structures even if they are morphologically less qualified for breakwater construction according to the international standards. The findings also suggest that Lumachel rock boulders followed by sandstone boulders in the second place are more durable and therefore are a better choice for the construction of stable jetties.