Geology topics

Robert T. Paine

Publications and source records attributed to Robert T. Paine.

3 recordsLinked to original sources

USGS2025

O Romeo! Environmental DNA could prevent a tragedy for the elusive Chucky Madtom (Noturus crypticus)

Using environmental DNA (eDNA) surveillance methods, we report the first evidence of the persistence of the Chucky Madtom ( Noturus crypticus ) in Little Chucky Creek, Tennessee, which has been absent from conventional surveys since 2004, and in Dunn Creek, Tennessee, where it was last collected in 1940. This highlights the utility of eDNA for detecting cryptic, rare fish species that may persist at extremely low population densities when conventional surveys fail, as well as its effectiveness as a contemporary tool to guide targeted conventional sampling efforts; however, it is not intended to replace the ‘in hand’ detection of the species.

Tennessee↗

USGS2024

Environmental DNA reveals invasion of Puerto Rican waterways by non-native Clarias catfish

The Sharptooth walking catfish ( Clarias gariepinus ) is native to parts of the Middle East, Asia, and Africa but is one of the world's most invasive freshwater fish species. The species’ ability to invade is partly due to its ability to breathe atmospheric oxygen, thereby avoiding hypoxia or poor water quality in receiving waterbodies; further, it can crawl over moist land to disperse to new systems. In 2018, two individuals purported to be Sharptooth walking catfish were collected and identified within the Canal de Patillas, a canal in the Guayama municipality in southeastern Puerto Rico. Several other specimens were also collected the following year. Given that this invasion was in its infancy, environmental DNA (eDNA) surveillance was employed as a rapid and efficient surveillance tool to help delineate the extent of this invasion. Water samples were collected and analyzed for Clarias eDNA from 66 sites encompassing a wide range of habitats in canals, lakes, and a river surrounding the area where they were first reported. Using eDNA-metabarcoding, we detected Clarias eDNA at 40 of the 63 sites throughout the sampled waterbodies. Furthermore, our molecular analysis indicated that the Whitespotted Clarias ( C. fuscus ) is the likely invader, and the original specimens, classified as C. gariepinus , were misidentified based on the use of morphological rather than genetic features for species classification. Environmental DNA surveillance indicated that the distribution of Clarias catfish in this system is substantially more extensive than previously documented. These findings suggest that additional survey efforts could help determine the invasion's full spatial extent and leading edge to inform the scope and scale of any potential management responses.

Puerto Rico↗

USGS2016

Historical baselines and the future of shell calcification for a foundation species in a changing ocean

Seawater pH and the availability of carbonate ions are decreasing due to anthropogenic carbon dioxide emissions, posing challenges for calcifying marine species. Marine mussels are of particular concern given their role as foundation species worldwide. Here, we document shell growth and calcification patterns in Mytilus californianus , the California mussel, over millennial and decadal scales. By comparing shell thickness across the largest modern shells, the largest mussels collected in the 1960s–1970s and shells from two Native American midden sites (&sim;1000–2420 years BP), we found that modern shells are thinner overall, thinner per age category and thinner per unit length. Thus, the largest individuals of this species are calcifying less now than in the past. Comparisons of shell thickness in smaller individuals over the past 10–40 years, however, do not show significant shell thinning. Given our sampling strategy, these results are unlikely to simply reflect within-site variability or preservation effects. Review of environmental and biotic drivers known to affect shell calcification suggests declining ocean pH as a likely explanation for the observed shell thinning. Further future decreases in shell thickness could have significant negative impacts on M. californianus survival and, in turn, negatively impact the species-rich complex that occupies mussel beds. .

Proceedings of the Royal Society B↗