“Feeding requirements of white sharks may be higher than originally thought”

                                                                 

Hello, welcome back to the final entry on Great White Sharks blog. Last week’s topic focused on phylogenetic trees and the different traits the chosen trees observed about the Great White Shark. In order to close out our series on Great White sharks, this week I will be dissecting a scientific research paper that solely focuses on Great White Sharks. The paper being reviewed focused on the metabolic rates derived from swimming speeds to suggest the feeding requirements of Great White Sharks. This paper was an observational experiment. The scientists used a combination of estimates of swimming speeds and measurements of standard in young white sharks to estimate fuel routine metabolic rates. Simply put, they estimated the swimming speed and their averages and the measurements of the standard metabolic rate, SMR, for young white sharks in order to come up with a routine metabolic rate, RMR.  An SMR refers to the minimum metabolic rate needed in order to sustain life at a specific temperature, while an RMR refers to how often an organism should be consuming food in order to keep their fuel sources up. 

Research that focuses primarily on the Great White shark are space due to the fact that they live in a range, deep sea, that people can not really access that easily. Great White sharks are also very dangerous apex predators, so being able to capture a few and holding them in captivity would not only be ethically wrong but it would prove to be difficult.  Apex predators are predators at the top of the food chain with little to no natural predators. This observational research paper goes into depth about how Great White Sharks time their feeding in conjunction with pinniped colonies. Pinniped colonies refer to seals, which are one of the prey of the Great White Sharks. Using one of the few research papers that focused on Great White Sharks, the authors hypothesized that the Great White Shark would not require to feed as often as others, and could in fact go for longer periods of time without feeding.

The scientists combined estimates of swimming speeds and RMR to estimate feeding requirements of Great White Sharks at an NZ fur colony in Neptune Islands, South Australia.  They observed over 9,000 swim speed estimates, and when all of the data was collected what the scientists discovered was that Great White Sharks actually feed more frequently than what was previously suggested,  30kg of marine blubber for 1.5 months (44.1 days), was actually 30kg of marine blubber fro 14.8 days.

The paper was able to show the relationship between the apex predator, the Great White Shark, and their prey. Since the scientists were able to observe the feeding pattern of the Great White Sharks when they were targeting the seal colonies, they were able to not only observe the feeding intervals but the behavioral patterns that go into how the Great White Sharks decide on what to eat. Through continuous observation and data collecting they were able to hypothesize that the reason, the Great Whites were targeting one type of prey for the period they were around the Neptune Island was due to the fact that it was less energy consumptive for them to stick to preying on one type of prey as opposed to different types. They observed that the Great White Sharks also stuck to mainly targeting the newly born seals since it would be easier for them to consume the newborns due to having to exert less energy in a tussle. Their continuous watching showed them that the Great White Sharks feeding intervals and even feeding behaviors were not so random at all, and even more so it showed them some of the steps the Great White Sharks took in order to expend less energy.

As I wrap up the last blog, there are two questions I chose to answer in regard to the research paper I chose. The two questions are:

A) How are these findings unique/new/unusual?

C) How do these findings apply to broader issues in science and/or the world?

 

A) These findings are groundbreaking because they not only dispel the false notion about Great White Sharks and their feeding patterns and RMR, it also adds to the already minuscule amount of observational research on Great Whtie Sharks. As previously mentioned, Great White Sharks are apex predators that live at a range that we as people can not so easily get to, so the amount of research and data that is collected on them is next to nothing. Having an extra piece of data that scientists swill is able to use in the future to build even better experiments that will maybe one day lead to breakthroughs in the way that we as people understand the different ecological environments on the planet.

 

C) The study could be used as a tool to further understand the roles of apex predators and the effects that they have on their own ecology. The research can hopefully one day be used in the future as a  blueprint in how to approach studying certain relationships in the environment particularly those of predators that we might not have that much access to.

 

 

Thank you so much for continuously coming back to my blog every week. I hope I was able to share new information about Great White Sharks with you. If you are interested in reading the full research article, it will be linked below. 

 

Citation: Semmens, J., Payne, N., Huveneers, C. et al. Feeding requirements of white sharks may be higher than originally thought. Sci Rep 3, 1471 (2013).

Link: https://www.nature.com/articles/srep01471#citeas