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Important Marine Mammal Areas


minke whale

Recently, I posted about Important Marine Mammal Areas (IMMA), but I took it down temporarily because a significant press release needed to precede it to avoid dilution of the information through social media posts. I’m creating this second post to provide more information.

IMMAs are officially defined as discrete portions of habitat crucial for marine mammal species. They have the potential to be delineated and managed for conservation purposes.

The role of IMMAs is to identify significant areas that can inform future conservation designations. Marine mammals serve as excellent indicators of ecosystem health as they depend on it, and recording their presence can be relatively straightforward. These areas aid in identifying overlaps between high human activity zones and critical habitats, allowing the management of risks through the introduction of guidelines or regulations. Risks may include oil spills, ship strikes, marine mammal bycatch, or the effects of underwater noise.

IMMAs Important Marine Mammal Areas that cover Mount's Bay.

Historically, Marine Conservation Zones (MCZ) and Special Areas of Conservation (SAC) have either not been designated for marine mammals or, if designated, lack necessary controls for their protection. One challenge with static marine areas is that marine mammals cover vast distances, and what appears important to them one year may not have high numbers in subsequent years. Hotspots shift due to oceanographic cycles over varying timescales. Even designated areas like The Bristol Channel Approaches Harbour Porpoise SAC lack protective measures for the designated species. In essence, little has changed in this domain. An interesting note is that this SAC’s area is not designated as an IMMA, contributing to the complexity of this challenging field. Obtaining reliable and robust data can be challenging, limiting the scope and range of designations.

In reality, the most effective way to protect marine mammals is to identify and control activities impacting them, a step not currently in practice. However, IMMAs might offer insights into where it’s crucial to initiate activity controls first.

The reason we consistently dedicate a significant amount of time to collecting and processing data on our tours is to advance knowledge and contribute to the designation processes. While our area may be relatively small in the grand scheme, it serves as an indicator of trends. The wealth of data collected over an extended period enables us to conduct various analyses. For instance, we can examine how the distribution of marine mammals in Mount’s Bay changes across tide cycles, allowing us to pinpoint in great detail the factors influencing their distribution. This detailed understanding is crucial in developing insights into their ecology and, consequently, how human activities might impact them.

common dolphins