Environmental and pathological factors affecting the hatching success of the two northernmost loggerhead sea turtle (Caretta caretta) nests

Abstract

In recent years, the report of loggerhead sea turtle (Caretta caretta) Mediterranean nesting range has expanded together with new records of nests becoming northward on the Italian coastline of the Tyrrhenian and Adriatic seas. These areas are characterized by intensive human activities, such as tourism, fishery, and marine traffic, all possibly involved in the influence of the use of coastal habitat by marine species. These anthropic threats, in addition to the natural ones and the changing environmental characteristics of the beach, may influence the growth of microorganisms causing hatching failures. Among microorganisms, fungal infection by the genus Fusarium (Link, 1809) is considered one of the main causes of globally declining sea turtle populations. In summer 2021, the two northernmost worldwide loggerhead sea turtle nests were monitored along the Northern Adriatic coastline (Veneto, Italy). These first records may potentially candidate this area as suitable for a large part of the loggerhead turtle’s life cycle and it could represent a minor sea turtle nesting area that, according to Prato and colleagues, remained unnoticed due to the lack of specific monitoring. Sea Turtle Egg Fusariosis (STEF) was deemed to have deeply compromised the hatching success of the northmost one. Climate change and anthropogenic impacts have been scored as one of the highest hazards to sea turtle health and could have played a role in the STEF development. Environmental changes, human activities, and emerging pathogens deserve the highest attention in terms of health research, and conservation management.

Investigation on anthropogenic and opportunistic factors relevant to the incidence of stranded loggerhead sea turtle Caretta caretta along South Tyrrhenian coasts

“…In 2021, from the Italian coasts, 244 nests were reported. Specifically, both Campania and Calabria coasts (53 and 77 nesting sites, respectively) have been chosen for turtle spawning (Pietroluongo et al, 2023). However, these beaches are characterised by a high flow of tourism that may threaten eggs and hatchlings, as well as the development of new rookeries.…”

Sublethal Effects of Polystyrene Nanoplastics on the Embryonic Development of Artemia salina (Linnaeus, 1758)

“…Indeed, it has been shown that zooplankton, during its grazing activity, cannot distinguish micro and nanoplastics from food, reducing the consumption of organic particles derived from primary producers [25,26]. The entry of plastic nanoparticles into zooplankton organisms is reflected in the impact on large aquatic organisms that ingest zooplankton and indirectly absorb microplastics, causing biomagnification and bioaccumulation [27][28][29]. Indeed, the negative effects of the accumulation of plastics as well as other emerging contaminants such as heavy metals (arsenic, cadmium, and lead) in sensitive target organs such as the gut have been recorded [30].…”