Researching the role of Laguna Yalahau as an elasmobranch nursery area in the past and present
It´s early in the morning as we stand in the fishing piers of Chiquilá, and just as the sun is about to rise, a full moon is settling on the other side of Yalahau Lagoon.
Dawn at the fishing pier of Chiquilá. Photo © Ramón Bonfil
Full moon settling and bathed by the rising sun. Photo © Ramón Bonfil
The view is magnificent and provides a wonderful setting for our first day of work. We are waiting for fishers to return from their night of fishing and see the catch they bring, and what they can tell us about the sharks and rays of this coastal lagoon on the north shore of Quintana Roo.
Laguna Yalahau Lagoon is a shallow (max. depth about 4 m) 32 km-long coastal lagoon spanning an area of 312 km2 inside the Area for Protection of Flora and Fauna of Yum Balam.
The Area for Protection of Flora and Fauna of Yum Balam, comprises the entire Laguna Yalahau and surrounding land area. Photo © Ramón Bonfil
Fisheries have been the main activity in the region since the early 20th Century, but the ‘discovery’ of Holbox as a top destination for international tourism at the end of last century has changed sharply the economy and ecology of the area. The lagoon is a beautiful area for ecotourism, where the public can see several bird species, manatees, fishes, and rays. Red and other mangroves surround a large part of the lagoon and the bottom is largely covered by seagrasses.
Red mangroves and seagrasses are the main flora of the lagoon. Photo © Ramón Bonfil
A sea eagle nesting in Laguna Yalahau. Photo © Ramón Bonfil
The purpose of our project is to investigate the role of this coastal lagoon as a shark and ray nursery area about 40-50 years ago and in the present. With this in mind, our first year of work has focused on interviewing older fishers who knew about the ecology and fisheries of this area when they were young, and through semi-structured interviews, we try to recover this information from them to reconstruct which species used Laguna Yalahau as a nursery area decades ago, and which were specific details about each species´ utilization of this place as a nursery area: birthing season, time-span of occupancy, spatial distribution in the lagoon, repeatability of their utilization, etc. My graduate students loved this type of work full of social interaction with incredibly knowledgeable people who have lots to teach us about the place, its history and past status.
Interviewing old fishers in Holbox to recover information from the past. Photo © Ramón Bonfil
Once we begin our fieldwork here, we will obtain current data to compare with the past. This will allow us to detect positive and negative changes in the ecological function of this place as a nursery area for sharks and rays, identify the main factors responsible for the negative change, and suggest actions for the recovery of the ecological role of this site as an elasmobranch nursery area.