The ocean sunfishes of the family Molidae comprise one of the tetraodontiform clades with the least known fossil record. Here, we report on what appears to be an isolated paraxial ossicle likely pertaining to the Molidae from a widely known marine vertebrate-bearing deposit of Southern Italy, i.e., the Miocene Pietra Leccese formation of Apulia. Thus far, paraxial ossicles are exclusively known from the genus Mola; however, the possibility that some extinct species of Ranzania or Masturus developed paraxial ossicles cannot be definitively ruled out, hence the attribution of the fossil described herein to an indeterminate taxon of the family Molidae. A careful scrutiny of palaeoichthyological literature reveals that, besides contributing to the meagre Mediterranean and global fossil record of the Molidae, the Apulian ossicle may be regarded as the best candidate to represent the first fossil find of the genus Mola from the Mediterranean Basin. In light of the environmental preferences of extant molids, the occurrence of an ocean sunfish in the Pietra Leccese matches well the warm-water, highly productive, outer neritic setting witnessed by this sedimentary unit and its fossil content. Considering also that the Miocene has been recognised as a time span of increased abundance and diversity of ocean sunfishes worldwide, our find should encourage the quest for new, hopefully articulated specimens of molids in this celebrated fossiliferous limestone.
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RBINS Staff Publications 2021 OA
The role of phytoplankton as ocean primary producers and their influence on global biogeochemical cycles makes them arguably the most important living organisms in the sea. Like plants on land, phytoplankton exhibit seasonal cycles that are controlled by physical, chemical, and biological processes. Nearshore coastal waters often contain the highest levels of phytoplankton biomass. Yet, owing to difficulties in sampling this dynamic region, less is known about the seasonality of phytoplankton in the nearshore (e.g., surf zone) compared to offshore coastal, shelf and open ocean waters. Here, we analyse an annual dataset of chlorophyll-a concentration—a proxy of phytoplankton biomass—and sea surface temperature (SST) collected by a surfer at Bovisand Beach in Plymouth, UK on a near weekly basis between September 2017 and September 2018. By comparing this dataset with a complementary in-situ dataset collected 7 km offshore from the coastline (11 km from Bovisand Beach) at Station L4 of the Western Channel Observatory, and guided by satellite observations of light availability, we investigated differences in phytoplankton seasonal cycles between nearshore and offshore coastal waters. Whereas similarities in phytoplankton biomass were observed in autumn, winter and spring, we observed significant differences between sites during the summer months of July and August. Offshore (Station L4) chlorophyll-a concentrations dropped dramatically, whereas chlorophyll-a concentrations in the nearshore (Bovsiand Beach) remained high. We found chlorophyll-a in the nearshore to be significantly positively correlated with SST and PAR over the seasonal cycle, but no significant correlations were observed at the offshore location. However, offshore correlation coefficients were found to be more consistent with those observed in the nearshore when summer data (June–August 2018) were removed. Analysis of physical (temperature and density) and chemical variables (nutrients) suggest that the offshore site (Station L4) becomes stratified and nutrient limited at the surface during the summer, in contrast to the nearshore. However, we acknowledge that additional experiments are needed to verify this hypothesis. Considering predicted changes in ocean stratification, our findings may help understand how the spatial distribution of phytoplankton phenology within temperate coastal seas could be impacted by climate change. Additionally, this study emphasises the potential for using marine citizen science as a platform for acquiring environmental data in otherwise challenging regions of the ocean, for understanding ecological indicators such as phytoplankton abundance and phenology. We discuss the limitations of our study and future work needed to explore nearshore phytoplankton dynamics.
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RBINS Staff Publications 2022
