Saving sharks from stranded eggs
Valentina is hoping to help improve the survival chances of unborn shark and ray embryos that wash ashore in mass strandings of their egg cases. There are times of the year at Chile’s Changa Beach when shark and ray eggs tend to be washed ashore – often after storms and strong surges. She will be caring for stranded eggs as a conservation measure and establishing methodologies to replicate this practice in other breeding areas.
Valentina Hevia-Hormazábal
As a marine biologist with experience in the ecology of marine environments, I specialise in bycatch species, chondrichthyan embryology and artisanal fishing. In 2018, I started working as a laboratory technician and associate researcher at the Chemical Oceanography and Phytoplankton laboratories, both of which are at the Universidad Católica del Norte (UCN) in Chile, and currently I am a PhD student in applied biology and ecology. In 2022 and 2023, under the supervision of Dr Bustamante and MSc Acuña, I began collecting washed-up egg cases of chondrichthyans, an activity that became the basis for the reintroduction of shark...
A tale of a stranded mermaid (purse): re-wilding endemic elasmobranchs impacted by kelp harvesting
We aim to improve the survival rate of chondrichthyan embryos by caring for stranded eggs as a conservation measure.
A massive shallow-water kelp forest is located off Changa beach in Coquimbo Bay. Many species make use of this ecosystem, including sharks, skates and humans. The harvesting of kelp may decrease the habitat available to chondrichthyans that use the kelp for egg laying and as a nursery area. We take human development and sustainability into account when collecting egg cases and returning juvenile chondrichthyans to the wild, and propose a novel methodology for conservation plans.
In studies carried out in Coquimbo Bay, the following chondrichthyan species have been identified: Peruvian eagle ray Myliobatis peruvianus, Chilean eagle ray M. chilensis, apron ray Discopyge tschudii, raspthorn sandskate Psammobatis scobina, short-tail fanskate Sympterygia brevicaudata, Chilean angelshark Squatina armata, speckled smooth-hound Mustelus mento, common thresher Alopias vulpinus and spiny dogfish Squalus acanthias.
Some species deposit their egg cases in the kelp that is present in the bay at certain times of the year, and when it washes ashore as a result of storms and strong surges the egg cases also end up on the beach. Similarly, some species deposit egg cases in marine debris that on occasion is also washed up onto the beach. In most cases, the eggs in the cases have not hatched and some of them, albeit a minority, are fresh.
At Changa beach, in the southern part of Coquimbo Bay, at certain times of the year large amounts of kelp are washed ashore and chondrichthyan egg cases are attached, often to the red seaweed Gracilaria chilensis. Some of the egg cases do not correspond to chondrichthyan species known to be in the bay, which indicates that further research in the area is necessary.
- To improve the survival rate of chondrichthyan embryos by caring for stranded eggs.
- To establish methodologies so that this action can be replicated in other breeding areas.