Lab 1 Paper: eDNA Shark Diversity Flashcards
Name and describe two advantages of monitoring elasmobranchs with eDNA compared to traditional
monitoring techniques?
Traditional monitoring techniques are resource intensive, selective and dependent on taxonomic expertise as well as being invasive and traumatic
Outperform traditional methods for diverse taxa
More cost-effective and non-invasive
Easy to standardize and no taxonomic expertise
Describe two disadvantages of using eDNA to determine elasmobranch abundance and richness
DNA in ocean water degrades beyond detectability within a few days, only detecting recent sharks in the area
Taxonomic resolution is dependent on the chosen markers
Taxonomic ambiguity due to limited sequence variability
Difficulty distinguishing closely related species
Estimating abundance is not cut and dry
Why are sharks vulnerable to overexploitation?
They are perceived to be in competition with fishers and dangerous in nature (untrue)
They have slow growth rates and low fecundities, particularly vulnerable to overfishing
According to the paper, why are the Bahamas, New Caledonia and Chesterfield more diverse (i.e.
higher richness) than the other sampling locations?
The Bahamas has a shark sanctuary status and heavy protection so it has the least fishing pressure.
New Caledonia and Chesterfield were found to be so diverse because they are still very pristine ecosystems further away from the capital. Less pressure
Briefly describe the issues with the genera Carcharhinus, Rhizopronodon and Negaproprion
identification with the eDNA sampling technique?
100% sequence identity matches with more than one species
Carcharhinus is taxonomically problematic and polyphyletic
Rhizopronodon and Negaproprion are less speciose
Very closely related species within these genera are often identified from one sample.