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MOVEMENT MOVEMENT ECOLOGY OF ECOLOGY OF
APEX APEX PREDATORY PREDATORY
SHARKSSHARKS
By: Dr. Neil Hammerschlag
Why Study Movement?
Ecological & Evolutionary Processes are linked to movement
Understanding movement management & Conservation strategies
Restoring degraded habitats
Preventing spread of
invasive species
Protecting wildlife
Shark satellite tagging
Recent advances in satellite tagging and tracking are allowing scientists to “spy” into the secret lives of marine animals
We are currently using satellite tags to track the movements of shark species in the subtropical Atlantic
The goal of this work is to understand the migratory routes and residency patterns of these sharks to identify “hot spots” in place and time that are critical for mating, giving birth and feeding as well as locations where these animals are vulnerable to destructive fishing
By characterizing and identifying these hot spots, we can help supply policy makers with the data they need to implement effective management strategies that will improve conservation for these species.
http://vimeo.com/43678265
Possible Questions
What is the distribution of the 3 sharks? How do they differ?
Are their movements correlated with any environmental conditions (sea-surface temperature, chlorophyll content)?
What types of habitats do they use (e.g. reef, seagrass, open-ocean)? How would you characterize their eco-type (e.g. coastal, semi-costal, pelagic)?
Could there movements be related to diet?
Possible Questions
What jurisdictions do they inhabit or move through (e.g. Florida waters, international waters, marine protected areas)?
To what extent is shark habitat use divided among different marine protected and political-economic zones?
What areas are sharks most vulnerable to fishing?
Real time data
Excel database for satellite tagged sharks Bull shark, tiger, hammerhead shark Excel worksheet for each individual of each
species Size – Sex - Date – Latitude - Longitude
Resources
Online curriculum - http://rjd.miami.edu/education/high-school-curriculum
FL Natural History Museum – Education – Biological Profiles
Google Earth NOAA Spatial registry
http://egisws02.nos.noaa.gov/cmspgisdataregistry/ MPA Atlas - http://www.mpatlas.org/ NOAA Data tools
http://cmsp.noaa.gov/data-tools/index.html Global shipping lane
http://geocommons.com/maps/5254
Bahamas
Mercury Toxicity
As apex marine predators, sharks are susceptible to mercury contamination through bioavailability and bioaccumulation of mercury via natural food web cycles. Mercury exists in the environment in many forms from natural elemental mercury (Hg) to toxic methyl mercury (MeHg). Some of this mercury is naturally occurring while some is derived as waste from anthropogenic sources such as power plants, incinerators, and industrial plants. Bacteria can convert total mercury into the toxic form of MeHg, which is then available to the food chain.
By examining mercury concentration in sharks, a top-down approach, we may learn about mercury contamination through the entire food web. We will also learn about contamination in certain species of shark, and what that means to the individual animal. Not only are sharks at risk to mercury contamination but humans consuming shark meat are also at risk to contamination, exhibited by standardized human health advisories and thresholds.
This may be useful when considering human health advisories, such as the Federal Drug Administration’s 1.0 μg/g (ww) action level for human health concerns.
http://vimeo.com/45969895
Possible Questions
Which species is at most risk to mercury contamination?
How do mercury levels relate to human health thresholds?
What does mercury contamination mean to sharks? Does size of shark and its mercury level relate to size
of prey item? Can mercury affect overall shark populations? Can total length be used as an estimator of muscle
mercury (per species)? What is the source of mercury in southern Florida? Do species that eat the same prey items accumulate
similar levels of mercury in their muscle tissue?
Real time data
Excel database for Mercury in Sharks Excel worksheet for 500 samples Size – Species - Sex - Date – Latitude –
Longitude – Mercury Concentration Hg & MeHg
Project description & meta-data
Resources
Online curriculum - http://rjd.miami.edu/assets/pdfs/learning-tools/high-school/MODULE%205%20Management,%20Conservation,%20Research%20and%20Actions%20-%20SECTION%203%20Mercury%20Toxicity%20Data.pdf
NIH — Mercury EPA — Pollutants WHO — Mercury MercuryPoison.com — Seafood
Consumption
http://vimeo.com/27639411