In the late 1800’s an event occurred which would forever change 
the Bay area. Phosphate was discovered in ancient Pliocene deposits 
along rivers and underground throughout the region. Mining operations 
rapidly expanded to strip the region of its valuable mineral deposits, 
and in fact the growth and competition which accompanied this new 
industry rivalled the 1840’s gold rush in size and in notoriety. 
Regardless, this singular discovery would eventually change the entire 
economy of the region, and with it the actual physical nature of 
Southwest Florida as we know it today. This would be accomplished not 
just through mining operations themselves, but through the physical 
changes imposed on shoreline shipping communities such as Tampa and its 
relatively pristine Bay ecosystem. By 1908 when the first large vessels 
entered Tampa Bay to haul phosphate rock out, the die was cast for 
physical alterations to the entire Bay system. To illustrate the impact, 
it is necessary to discuss phosphate very briefly. 
Twenty percent of the world’s phosphate production and 80% of all 
United States phosphate output takes place just east of Tampa and 
Sarasota Bays (Florida Phosphate Council, personal communication). 
Approximately 50% of all tonnage leaving Tampa Bay is composed of 
phosphate related products. Even though this is down from 80% just 10 
years ago (primarily due to expanding foreign sources and a depressed 
fertilizer market), it still makes the Port of Tampa alone one of the top 
10 ports tonnage-wise in the United States. By comparison, the ports of 
New Orleans and Houston may be far greater in physical size; but 
considered as a whole, the ports of Tampa Bay together are now the 4th 
largest in the country in terms of both tonnage and vessels called to 
port (Florida Ports Council, personal communication). Last year alone, 
these ports handled over 50 million tons of waterborne commerce -- more 
than any other port in the southeastern United States. 
As one looks at the 70-some miles of 43 foot deep channel 
traversing the Bay (Figure 1), keep in mind that its initial development 
was almost exclusively related to phosphate trade and the need for deeper 
channels to allow deep-draft ocean-going vessels to navigate. Although 
petroleum (and its related products) is a major maritime cargo and is the 
principal incoming product to Tampa Bay, it is historically a distant 
second-runner in use of the channels compared to phosphate products. 
Other major cargoes include cement, coal, animal feeds, scrap metal, and 
lumber. Several cruise lines are also located in Tampa Bay ports. 
Before discussing the channels and port development impacts, 
mention of a quirk regarding the channel and its strategic importance for 
Tampa Bay is in order. Tampa Bay, and specifically Port Manatee, is the 
closest United States deepwater port to the Panama Canal. ALL large 
ships sailing in and out of Tampa Bay must use the main ship channel, and 
in turn, must pass under the Sunshine Skyway Bridge. Besides the 
significance this bridge has regarding circulation problems in the Bay, 
ironically this so-called Gateway to Tampa Bay can also be a closed gate. 
An act of war or a navigational error resulting in collision with the 
bridge (as occurred several years ago) can bring the bridge down into the 
channel, blocking all navigation in or out. In fact, contingency plans 
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