MelaceucaSleuthing

A HISTORY MOST FOULED DETECTIVE THUMB-A-RIDE (SUPER SLEUTH)

As long as ships have been in existence, they have helped aquatic species move around the globe. Ballast water (water stored in large tanks on cargo ships and tankers to stabilize them and prevent roll-overs) is considered the most common way aquatic organisms are transported. However, the hulls of ships also move organisms around. Think about the wooden ships of old. They carried bunches of organisms around with them; some attached directly to the hull below the water's surface and others hiding in shallow holes in the hull made by boring organisms (not uninteresting organisms, but those with the ability to chew or drill into the wood). Today, most commercial ships are built with steel or fiberglass hulls. While organisms can't chew holes in these hulls, they can still attach to (or foul) the hull surface, propeller, and other underwater parts of the ship, and travel from port to port. One way to reduce this fouling problem is to paint the hull surface with a coating that prevents or discourages organisms from attaching.

Compare the characteristics* of historical wooden ships to those of modern ships as they influence hull fouling and the movement of aquatic invasive species.

	Wooden Ships		Modern Ships
	Ship Specs	Effect on Hull Fouling	Ship Specs	Effect on Hull Fouling
Speed	4-5 knots, up to 10-12 knots	Slow-moving ships enabled organisms to remain attached; ships took weeks or months to reach destinations	20-25 knots	Speed knocks organisms off hull; journeys shorter, increasing survival rates; ships moving around world at much faster pace
Time in port or at anchor	Months	Communities of organisms able to attach firmly and grow; seaweed could grow 3 feet thick	Hours	Fewer coastal organisms able to attach due to short time spent in ports
Hull material	Wood	Organisms attach to hull or burrow directly into hull	Steel, aluminum, fiberglass	Organisms attach to hull
Hull Protection	Bottom (keel) covered by a layer of lead or by a layer of animal hair covered with a second thinner layer of wood	Many areas remained unprotected, and were destroyed over time by shipworms (a type of mollusks) from inside out and by gribbles (tiny crustaceans) from outside in	Antifouling paints and coatings	Toxic to organisms; hull remains relatively clean; some organisms developing tolerance to paints; some paints banned due to extreme toxicity (to organisms in water as well as on hull)
Distances Traveled	By end of 18th century, most of world explored; by mid-19th century, bustling global shipping	Tremendous movement of marine organisms all over the world in concert with the increased shipping activity	Globally, within weeks	Marine organisms are rapidly transported around the globe
Ballast (for stability and trim)	Dry ballast used â€“ rocks, stone, gravel, debris, sand, iron	Seeds of plants transported; dry ballast thrown over side into channels/harbors	Water	1000s to 10s of millions of gallons of water carried, containing numerous organisms (from the microscopic to schools of fish); primary way marine organisms moved around globe

*Source: Carlton, James T. 1992. Blue Immigrants: The Marine Biology of Maritime History. The Log of Mystic Seaport 44(2):31-36. Mystic Seaport Museum, Mystic Connecticut.

Using the information in the above table, fill in the blanks in the following press release offering free passage to marine organisms. Then hit “Print” to print out your own copy.

FOR IMMEDIATE RELEASE

Date:

Location:

Contact: Detective Thumb-a-Ride

Captain announced today that the Company is offering free passage to all marine organisms on the ship . The is leaving its dock based in on Friday next, and will be headed to by way of and . The trip is expected to take ________________ days.

The ship’s accommodations are luxurious, with a hull of , plenty of room in the , and no anywhere. All interested passengers, be ye , , , or are welcome. First come, first aboard! No allowed.

Keep in mind that travel options by alternative ships are more . There may be or that hinder attachment or diminish the overall survival experience. Don’t get stuck in the , travel in style!

Captain also reminds all marine organisms that if it weren’t for ships, then .