Johanna Kohler

Cayman Islands Government · Department of Environment

The roughskin dogfish Centroscymnus owstonii, a deep‐sea shark, has a patchy global distribution, with most knowledge stemming from incidentally captured specimens. Using a deep‐sea remote lander video system, we observed multiple C. owstonii individuals alive on the footage at 1054 m off Little Cayman, Cayman Islands, Western Atlantic Ocean, marki...

Misty Groupers (Hyporthodus mystacinus) are one of the largest and most geographically widespread grouper species and one of the few grouper species known to occur at depths greater than 200 m. However, aspects of their basic biology, behavior, and ecology remain poorly understood, leaving significant gaps in our ability to evaluate their functiona...

The scalloped hammerhead shark (Sphyrna lewini), a critically endangered species with a decreasing global population, is characterised by its occurrence in large schools. Such schools are still observed today in the Pacific Ocean, but this is generally not the case in the Atlantic Ocean, and in the Cayman Islands not since the 1970s. Here we report...

Understanding how reef-associated sharks use coastal waters through their ontogeny is important for their effective conservation and management. This study used the horizontal movements of acoustically tagged Caribbean reef sharks (Carcharhinus perezi) to examine their use of coastal space around the Cayman Islands between 2009 and 2019. A total of...

The assessment of parameters population size and individual home range is important for effective conservation management of sharks. This study uses the novel application of photo identification (photo-ID) to BRUVS footage as a non-invasive alternative to tagging in order to generate individual capture histories. These were used in mark-recapture m...

The genus Etmopterus is the most speciose group of small bodied deep-sea sharks found throughout the tropical and subtropical Western Atlantic. Despite exhibiting a global distribution at the genus-level, the blurred lantern shark (Etempoterus bigelowi) is known only from a few records in the Western and Southern Atlantic Ocean. Through in-situ vid...

Baited Remote Underwater Video Stations (BRUVS) are widely used for monitoring relative abundances of fishes, especially sharks, but only the maximum number of individuals seen at any one time (MaxN) is usually recorded. In both the Cayman Islands and the Amirante Islands, Seychelles, we used photo-ID to recognise individual sharks recorded on BRUV...

In the Cayman Islands, we have been operating, in collaboration with the Cayman Islands Department of Environment, a “Sharklogger” programme - a citizen science initiative involving volunteer professional and recreational divers. Participating divers log all their dives, recording not only the presence but also the absence of sharks. Access to ful...

In April 2015, the Cayman Islands gave full legal protection to all sharks and other elasmobranchs throughout its Exclusive Economic Zone. This was the culmination of a research programme initiated in 2008 to determine the status of sharks in Cayman waters and assess the need for their conservation. A Facebook linked citizen science scheme and inte...

In April 2015, the Cayman Islands gave full legal protection to all sharks and other elasmobranchs throughout its Exclusive Economic Zone. This was the culmination of a research programme initiated in 2008 to determine the status of sharks in Cayman waters and assess the need for their conservation. A Facebook linked citizen science scheme and inte...