Venting Tool Changes in the Gulf Provide New Options for Anglers

Did you know anglers targeting reef fish such as grouper and snapper in the Gulf of Mexico are no longer be

Venting a red grouper

required to use venting tools to treat fish suffering from barotrauma. Barotrauma is the rapid expansion of gases inside a fish’s swim bladder due to changes in pressure when brought to the surface. Venting is the process of releasing these trapped gases by inserting a sharpened, hollow needle into the side of the fish, which has shown to be a useful method for returning fish back to depth. However, while venting can be attributed to increased survival rates for some species, research for many other is either lacking or inconclusive, particularly in deeper waters. In addition, new gear known as fish descending devices can be used to return fish back to depth without the need of venting in many cases. Research from the U.S. Pacific coast has shown that fish descending gear have been highly effective at increasing the survival rates of several species of released rockfish. It is hoped that these devices will have similar results for reef fish in the Gulf of Mexico and South Atlantic. Because of the reasons, the Gulf Council voted to remove the venting requirement. It is important to note, however, that both venting and descending devices are options of last resort and should only be used if fish can’t get back down on their own. Knowing when and how to properly use these devices is key to improving the survival rates of fish that are released.Are you new to fish descending gear?
While fish descending gear is not necessarily new, their use has been more prevalent on the west coast than 


A Seaqualizer Fish Descending
Tool being used to
return a red grouper
suffering from barotrauma

here in the Gulf and South Atlantic. Check out the following videos that show some examples of these devices.

Using the Fish Saver Descending Tool

http://youtu.be/bXmSAvpJHa0

Using a Utility Crate (aka fish elevator) Fish Descending Tool

http://www.youtube.com/watch?v=mhqjN-2bApg

Using the Seaqualizer Fish Descending Tool

http://www.youtube.com/watch?v=O4YktnnBLko

 To learn more about barotrauma, venting tools, and fish descending gear visit Florida Sea Grant's catch and release website.

Sawdust in the Water? Trichodesmium Algal Blooms

 Boaters and beachgoers in southwest Florida periodically observe what appears to be large mats of

“sawdust” floating on the water’s surface. What they are seeing is not the remnants of someone’s woodworking project, but a marine cyanobacteria (also known as blue green algae) called Trichodesmium.

Trichodesmium naturally occurs in tropical and subtropical waters including the Gulf of Mexico. When environmental conditions are right, Trichodesmium cells rapidly repro-duce resulting in a bloom of the cyanobacteria that can be visible by onlookers.

According to the Florida Fish and Wildlife Research Institute, Trichodesmium cells form long chains, called trichomes. Trichomes then can gather into colonies called “puffs” or “tuffs,” and these colonies can aggregate at the surface of the water and form large mats that can extend for miles (also called “sailor’s sawdust”). The amount of Trichodesmium on the surface may vary with time of day, as this species is capable of migrating up and down in the water column. Blooms generally occur offshore in nutrient-poor waters, but currents and winds can push them near shore.

Trichodesmium blooms can take on a range of colors depending on stage of the bloom. Healthy blooms are typically brown in color, while blooms in initial decay may take on a green appearance due to accessory pigments leaching out and exposing the cyanobacteria’s chlorophyll. When the chlorophyll begins to deteriorate the blooms appear white in col-or. Trichodesmium blooms are also reported to have a unique “sweet” smell when it decays and large blooms can turn the water red or pink when stressed cells leaks out water soluble, accessory pigments.

Unlike other algal blooms that occur in the region, Trichodesmium blooms are not related to coastal nutrient sources or pollution. Most or all of the nutrients Trichodesmium requires are taken up directly from the water.

Interestingly, the occurrence of Trichodesmium blooms in Florida is thought to be connected to weather events on the other side of the planet. Blooms in the Gulf of Mexico tend to occur between May and September, which is also a time of high storm activity in the Sahara Desert in Africa. Iron-rich dust from these storms are transported across the Atlantic Ocean by wind currents, and deposited into the Gulf of Mexico. Trichodesmium cells contains enzymes that utilize this high concentration of deposited iron to convert nitrogen into useable forms.

While Trichodesmium blooms can be aesthetically unappealing, it is not toxic and does not pose a health risk to humans. Ironically, Trichodesmium blooms are often seen prior to a Florida red tide bloom, which is a toxic algae that can result in numerous fish kills and human health issues.

 
Reference: http://myfwc.com/research/redtide/archive/historical-events/trichodesmium-fl-2004/

2013 Florida Seafood Brown Bag Webinar Series

Join the Florida Sea Grant Extension Programs from Collier and Miami-Dade Counties for the 2013 Florida Seafood Brown Bag Webinar Series. This year's sessions will focus on seafood health and saftety.
See below for dates and topics.
To register for this FREE program visit: http://2013seafoodsafetyseries.eventbrite.com/#