NOAA Teacher at Sea
Julie Karre
Aboard NOAA Ship Oregon II
July 26 – August 8, 2013
Mission: Shark and Red snapper Longline Survey
Geographical Area of Cruise: Atlantic Ocean off the Coast of Florida
Date: Friday, August 2 – Sunday, August 4, 2013
Weather Data from the Bridge
Friday – SW WINDS 10 TO 15 KNOTS
SEAS 3 TO 5 FEET
SCATTERED SHOWERS AND THUNDERSTORMS
Saturday – SW WINDS AROUND 15 KNOTS
ISOLATED SHOWERS AND THUNDERSTORMS MAINLY AFTER MIDNIGHT
SEAS AROUND 4 FEET
Sunday – W WIND 5 TO 7 KNOTS BECOMING VARIABLE AND LESS THAN 5 KNOTS
A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY AFTER 10PM
SEAS AROUND 3 FEET
Science and Technology Log
In this log we’ll take a closer look at the sharks we’ve brought on board:
The Atlantic Sharpnose has been the most abundant shark on our survey and will continue to be abundant for the rest of the cruise, even in the Gulf of Mexico. It is in fact one of the species that is on the Least Concern list in terms of its vulnerability. It is often a victim of by-catch and makes up 1/3 of the commercial landings of sharks in the United States. But being capable of producing offspring in abundance, the Sharpnose remains a steady species with moderate population growths. As indicated by its name the Atlantic Sharpnose is found all along the U.S. Atlantic coast and even as far as New Brunswick, Canada. When the Oregon II makes its way back into the Gulf of Mexico, it will likely continue to make an appearance on deck.
Photo Credit: Claudia Friess from her 2009 Longline cruise on the Oregon II. When we caught a Blacknose on this cruise it was too dark to get a good picture.
The Blacknose Shark shares a similar body with the Sharpnose, but is marked by a (drumroll please) black mark on its nose. Unfortunately, the Blacknose doesn’t share its abundance with the Sharpnose. The Blacknose is listed as Near Threatened due to its high mortality rates in shrimp trawl nets. The Blacknose is suffering a decline in its population. The Oregon II has only seen 5-6 Blacknose during this leg of the survey.
Photo Credit: Claudia Friess from her 2009 Oregon II cruise. Again, it was too dark to get quality photos of our Nurse Shark.
The Nurse Shark, the first big shark we cradled, is characterized by sedentary and relatively docile behavior. They are still relatively mysterious in their migratory behavior and the gene flow between populations. Recently, it has been shown in population decline in certain areas perhaps due to its vulnerability to catch, but also perhaps because of habitat alteration.
The Scalloped Hammerhead has been my favorite so far. A friend of mine characterized it as the hipster of the shark world. There is something truly magnificent about those wide-set eyes. Unfortunately, the Scalloped Hammerhead is Endangered. The Scalloped Hammerhead can be found in coastal temperate waters all around the world. In each of these regions, it is threatened by capture, mostly as by-catch in fishing gear, gillnets, and longlines. Hammerhead shark fins are also more valuable than other species because of their high fin count. The species is in decline.
The Bull Shark is a unique shark species because it can survive in freshwater for extended periods of time. This ability has caused it to be categorized as Near Threatened because it often gets caught in fisheries, but it is not a target species the way others are. Here’s what Kristin Hannan had to say: “Bull sharks’ ability to tolerate greater salinity extremes means that it is likely to be in more productive areas like at the input of rivers. The rivers which dump high levels of nutrients into the system spur on production, high nutrients means more phytoplankton, more phytoplankton means more small critters eating and so on up. These areas also mean hot spots for fishing activities as productivity means more fish, more fish means more predators, more interaction with gear, more possibilities for shark mortality.”
The Sandbar Shark, which we caught in abundance one night, is a widespread species in warm temperate waters. Studies have found that it is a long-lived species, but it does not reproduce quickly so it has become Vulnerable due to overfishing. The species is currently in decline. The Sandbar is considered valuable because of their fins, which are large.
The Tiger Shark is commonly found world wide in tropical and warm coastal waters. Aside from the Sandbar, it is the largest shark we have caught the most of. Fortunately, it is considered a fast-growing species with the ability to reproduce abundantly. It is not considered at a high risk for extinction, but the desire for fins makes the risk of further population decline a distinct possibility.
We have only caught 1 Night Shark during our survey. It is a Vulnerable species. It is prized mostly for its fins and meats and is caught in abundance off the coast of Brazil. Studies have shown that most of the Night Sharks landed were below 50% maturity, which is 8 years for males and 10 years for females. In the United States, the Night Shark is listed as a prohibited species.
When talking to Kristin about these sharks, she shared this about their reproduction, “All sharks are considered K-selected species like humans; we are late to mature, grow slowly and reproduce relatively few young comparatively to say a bony fish that might produce thousands of babies in its lifetime (s-selected). So when we talk about a tiger [shark] vs. a sandbar [shark] being more or less productive, it is definitely in relation to each other and not all fish. A tiger [shark] does produce more young than some other species but way less than the red grouper he goes after for dinner. This is why all sharks are so sensitive to fishing pressures; they have a considerably longer bounce back time.”
Personal Log
It’s hard to believe that over a week has passed, but given how much we have seen and done, it makes sense.
As I get more and more comfortable handling sharks and working on the boat, I have noticed a few things. My sister-in-law Elizabeth noticed a few years ago that my family has a love for responding to each other (and often friends and acquaintances) with movie quotes. The most commonly quoted movies in our family include The Big Lebowski, The Princess Bride, Blues Brothers, To Kill A Mockingbird, and many more. I am no exception to this family trend.
So while we’re all eagerly awaiting the call that a shark is on the hook, it occurred to me that this movie-quoting affliction had not escaped this trip. When a fish or shark is caught on one of our hooks, the fishermen call out “Fish on” to notify those of us handling to come over and retrieve the animal. I realized that this was no common call in my head, though. Each time I hear the “Fish on” I hear it more in the call of “Game Ooon” from Wayne’s World. I suppose that’s a hazard of anyone growing up in the 90s. What proves I am truly a Karre though is that when I’m talking to the shark I’m handling, asking and sometimes begging it to be still so I can remove the hook quickly and reduce its harm and pain, in my head the shark is responding “Oh I’m cooperating with you” in the voice of William H. Macy from the movie Fargo.
Did You Know?
There are over 6000 known coral species around the world. We have brought up several pieces of coral on our clips. Kevin found a bright red piece of coral, which prompted a lesson for us about how many red corals release an irritant that will make our skin burn and sting. Fortunately, that’s not what Kevin brought up!
