This article summarizes a new paper from the journal of fish biology and is cited as DOI: 10.1111/jfb.14592. The journal can be found here. 
As climate change continues to affect the world’s oceans, predicting the consequences of shifting food webs is important in understanding resource use patterns. Many sharks are opportunistic hunters; however, some species exhibit prey selectivity. Sharks that are selective with what they eat are at higher risk of extinction when their prey species are overharvested.
In the Gulf of Mexico, Clupeids and Sciaenids make up 69% of blacktip shark diets. This diet choice is consequential because of the potential disturbance and over-harvesting of these aforementioned fish species.
The team finds that, off the coast of Texas, clupeids comprised <2% of blacktip diets, while striped mullet (Mugil cephalus) and red drum (Sciaenops ocellatus) comprised >70% of identifiable prey. The scientists also find that larger blacktip sharks fed on prey higher up in the marine food web. Discovered prey includes other sharks and catfish.
The discovery that larger blacktip sharks feed on species higher in the food web fits shark science’s understanding that coastal sharks are foragers. It also suggests that sampled sharks’ sizes may limit the regional understanding of the blacktip’s role in the food web.
The decline in prey species, coupled with increased observed blacktip densities, is concerning. However, this study finds that blacktip shark diets may be more generalized than previously thought, which is very promising for blacktip conservation and management.