WEBVTT 00:02.736 --> 00:07.474 >>NARRATOR: On April 20, 2010,the "Deepwater Horizon" rig 00:07.474 --> 00:12.212 exploded in the Gulf of Mexico,killing 11 workers 00:12.212 --> 00:15.916 and setting off the largestaccidental marine oil spill 00:15.916 --> 00:20.187 in the historyof the petroleum industry. 00:20.187 --> 00:23.056 >>We haven't had an oil spillof this magnitude at this depth 00:23.056 --> 00:26.126 and in this environment. 00:26.126 --> 00:30.664 >>This was a systematic failureon the part of BP, 00:30.664 --> 00:33.066 the industry in general, 00:33.066 --> 00:36.937 and of the governmentregulatory regime. 00:36.937 --> 00:39.907 >>NARRATOR: Over the courseof nearly three months, 00:39.907 --> 00:44.144 roughly 4.9 million barrelsof South Louisiana crude 00:44.144 --> 00:49.616 gushed out of the Macondo welland into the Gulf of Mexico. 00:49.616 --> 00:53.220 >>It was beyond my worst fears. 00:53.220 --> 00:55.522 It was something I hopeI never see again. 00:55.522 --> 00:58.225 >>NARRATOR: The Macondowellhead was located 00:58.225 --> 01:01.962 at 5,000 feetbeneath the water's surface, 01:01.962 --> 01:05.399 discharging large amountsof oil and gas 01:05.399 --> 01:07.467 under enormous pressure. 01:07.467 --> 01:10.804 >>Most other spills areassociated with a surface breach 01:10.804 --> 01:12.339 from a tanker. 01:12.339 --> 01:14.908 The oil sits on topof the water. 01:14.908 --> 01:17.010 This was a completelydifferent situation. 01:17.010 --> 01:20.514 This was the first deepwaterblowout. 01:20.514 --> 01:22.449 >>NARRATOR:2.9 million gallons 01:22.449 --> 01:24.351 of the chemical dispersantCorexit 01:24.351 --> 01:28.322 were applied at the surfaceand near the wellhead 01:28.322 --> 01:33.293 to break up the oil and keep itfrom soiling sensitive marshes. 01:33.293 --> 01:35.862 >>Dispersants werea novel concept 01:35.862 --> 01:38.298 in terms of using themsubsurface. 01:38.298 --> 01:40.801 There's a great amount of angst,not only in the public, 01:40.801 --> 01:43.570 but among the federal agencies--what are the limits of this? 01:43.570 --> 01:46.406 Is this a good or bad thing? 01:46.406 --> 01:49.142 >>I don't think anybody knowswhat the answer to that is. 01:49.142 --> 01:53.013 I understand why the headsof agencies made the decision 01:53.013 --> 01:54.581 to use the Corexit. 01:54.581 --> 01:57.184 They were trying to averta worsening condition 01:57.184 --> 01:58.785 on the seashore, 01:58.785 --> 02:02.289 in the sensitive nursery areasand the estuaries. 02:02.289 --> 02:03.957 By making that decision, 02:03.957 --> 02:07.094 they made the conditions worseoffshore and at depth. 02:07.094 --> 02:10.597 It was a no-win situation. 02:10.597 --> 02:12.933 >>Trying to understandthe balance 02:12.933 --> 02:15.602 of those pluses and minusesin the long term 02:15.602 --> 02:19.239 is clearly somethingthat we have to find out. 02:21.942 --> 02:24.945 >>NARRATOR: Opinions on thefate of the oil vary widely. 02:24.945 --> 02:30.050 It is estimated that anywherebetween 13% to 60% of the oil 02:30.050 --> 02:33.387 remains in the Gulf of Mexico, 02:33.387 --> 02:38.258 potentially affecting ecosystemhealth for years to come. 02:38.258 --> 02:41.995 What will the long-termimpacts be? 02:41.995 --> 02:48.568 How long until the true extentof this disaster will be known? 03:14.494 --> 03:16.363 >>Major fundingfor this program 03:16.363 --> 03:18.699 was providedby the Batchelor Foundation, 03:18.699 --> 03:21.268 encouraging peopleto preserve and protect 03:21.268 --> 03:24.204 America's underwater resources. 03:33.513 --> 03:36.783 >>NARRATOR: The catastrophicoil spill in the Gulf of Mexico 03:36.783 --> 03:39.653 may no longer makeheadline news... 03:46.226 --> 03:51.832 ...but the response to thedisaster is far from over. 03:51.832 --> 03:55.102 Scientists from the government,academia, 03:55.102 --> 03:57.604 and independentresearch institutions 03:57.604 --> 04:02.075 continue to studythe impact of the spill. 04:02.075 --> 04:04.644 Among them is the facultyof the College of Marine Science 04:04.644 --> 04:07.114 at the Universityof South Florida, 04:07.114 --> 04:09.549 who became involved early on. 04:09.549 --> 04:12.819 >>We had research vesselssitting at the dock. 04:12.819 --> 04:15.922 We had personnel that hadexpertise in various areas 04:15.922 --> 04:20.961 related to the spill, and so wefelt that we needed to react. 04:20.961 --> 04:24.164 >>NARRATOR: The USF Collegeof Marine Science, 04:24.164 --> 04:29.269 located in St. Petersburg,Florida, is the home base 04:29.269 --> 04:30.737 for the Florida Instituteof Oceanography's 04:30.737 --> 04:34.007 research vesselWeatherbird II. 04:36.810 --> 04:38.411 >>We were among the firstvessels that were directly 04:38.411 --> 04:41.581 in the oil spill,and we worked closely 04:41.581 --> 04:43.316 with the federal governmentand with the state. 04:43.316 --> 04:45.519 And we did it for severalreasons, because, you know, 04:45.519 --> 04:49.422 we felt like it wasour responsibility. 04:49.422 --> 04:50.957 We are a public institution. 04:50.957 --> 04:53.560 We are here to servethe citizens of Florida, 04:53.560 --> 04:56.496 and there was tremendous concernabout what this will do 04:56.496 --> 05:02.169 to our economy, to our tourism,which has been a big issue. 05:04.171 --> 05:06.173 >>NARRATOR:Prior to theWeatherbird's 05:06.173 --> 05:09.943 first research cruisein May of 2010, 05:09.943 --> 05:12.646 a group of local researchersand faculty members 05:12.646 --> 05:14.848 at the College of Marine Science 05:14.848 --> 05:17.384 gathered to come upwith a strategy. 05:17.384 --> 05:18.885 >>We had a long discussion 05:18.885 --> 05:22.956 about what would bethe optimum sampling plan. 05:22.956 --> 05:24.591 >>We had a couple of reasons 05:24.591 --> 05:28.295 for expecting there to bea subsurface layer of oil. 05:28.295 --> 05:31.598 One is some experimentationthat was done 05:31.598 --> 05:35.735 that indicated the majorityof the oil released at depth, 05:35.735 --> 05:39.406 at tremendous pressure,will not make it to the surface. 05:39.406 --> 05:43.243 The pure physics of havingvery small droplets of oil-- 05:43.243 --> 05:44.945 which form naturally, 05:44.945 --> 05:46.847 but they're also createdintentionally 05:46.847 --> 05:49.482 by dispersants such as Corexit-- 05:49.482 --> 05:51.852 those oil dropletshave a very hard time 05:51.852 --> 05:55.088 fighting against the resistanceof the water on their way up, 05:55.088 --> 05:57.157 and they end upbeing stationary. 05:57.157 --> 06:01.294 >>NARRATOR: The USF scientistsalso knew 06:01.294 --> 06:05.765 that shortly after the spill,a different group of researchers 06:05.765 --> 06:08.768 working from the research vessel"Pelican" 06:08.768 --> 06:12.372 had discovered an underseahydrocarbon plume 06:12.372 --> 06:16.843 to the southwest of the"Deepwater Horizon" drill site. 06:16.843 --> 06:18.678 >>And that clicked for us, 06:18.678 --> 06:21.648 especially with our circulationmodels that suggested 06:21.648 --> 06:23.116 both a trajectoryto the southwest, 06:23.116 --> 06:25.285 but also to the northeastin the direction 06:25.285 --> 06:28.021 of the continental slopeand shelf of Florida. 06:28.021 --> 06:30.257 >>So that narrowed things downvery much, 06:30.257 --> 06:32.959 to the point where we could lookat the charts 06:32.959 --> 06:34.594 and pick a place and say, 06:34.594 --> 06:36.062 "This is likely to have oilat it." 06:36.062 --> 06:38.598 We also picked areas thatwe thought would not have oil 06:38.598 --> 06:39.866 for comparison. 06:39.866 --> 06:42.836 >>We wanted to cover areas 06:42.836 --> 06:45.405 that were of moreintrinsic importance 06:45.405 --> 06:48.475 to the state of Florida,as well as to cover regions 06:48.475 --> 06:50.877 that other investigatorsweren't covering. 06:50.877 --> 06:53.146 >>So we had a numberof stations selected 06:53.146 --> 06:55.048 at different distancesfrom the wellhead 06:55.048 --> 06:57.217 at different depthsthat were designed 06:57.217 --> 07:00.887 to intercept any unseen oilmoving toward the state. 07:00.887 --> 07:03.623 >>NARRATOR:Once at sea, 07:03.623 --> 07:06.393 it didn't take the researchersvery long 07:06.393 --> 07:08.361 to find subsurface oil. 07:08.361 --> 07:11.298 >>Finding it, we thought, mightbe like a needle in a haystack. 07:11.298 --> 07:13.733 But we found the oilwithin a few days. 07:13.733 --> 07:15.268 >>It was a thick plume. 07:15.268 --> 07:16.903 We were able to recognizetwo components-- 07:16.903 --> 07:19.806 one was at 400 meters thatspanned about 100 feet thick, 07:19.806 --> 07:21.775 and the other one was located 07:21.775 --> 07:25.445 between 1,000and 1,200 meters water depth, 07:25.445 --> 07:27.414 which was essentiallythe bigger plume, 07:27.414 --> 07:30.517 and that extendedfor upwards of 600 feet. 07:30.517 --> 07:33.286 We were able to see thesefeatures in the subsurface 07:33.286 --> 07:35.889 simply using a fish finder. 07:35.889 --> 07:40.660 >>NARRATOR: Once back in thelab, Dr. Hollander and his team 07:40.660 --> 07:45.065 ran chemical tests to confirmthe plume was made up of oil. 07:49.235 --> 07:52.672 Next, they matched,or fingerprinted, the plume 07:52.672 --> 07:57.077 to the oil released by theill-fated Macondo wellhead. 07:58.979 --> 08:01.348 And the researchdidn't end there. 08:05.952 --> 08:07.620 Since May of 2010, 08:07.620 --> 08:11.157 the scientists have maderepeated trips to the area. 08:11.157 --> 08:15.428 While at sea, experts usea number of instruments 08:15.428 --> 08:18.665 to collect datathat might provide clues 08:18.665 --> 08:22.502 on the environmental impactsof the oil spill. 08:25.572 --> 08:27.707 Water samples are collected 08:27.707 --> 08:31.077 using a device calleda Rosette sampler. 08:31.077 --> 08:33.913 >>A Rosette samplerhas various bottles 08:33.913 --> 08:35.348 that we can triggerat different depths. 08:35.348 --> 08:38.752 And the way we decide whatdepths to trigger at is based 08:38.752 --> 08:42.122 on sensors which are attachedto the Rosette Sampler. 08:42.122 --> 08:45.158 There's sensorsfor fluorescence, temperature, 08:45.158 --> 08:47.560 depth, and also light-scatter, 08:47.560 --> 08:50.663 and the light-scatteris a crude indication 08:50.663 --> 08:54.167 of where there might beoil droplets. 08:54.167 --> 08:56.603 >>The data from the sensorsis retrieved back 08:56.603 --> 08:58.972 through an electronic cableso that, on the ship, 08:58.972 --> 09:01.841 we can see the datain real time. 09:07.847 --> 09:09.849 >>NARRATOR: The scientistscollect water samples 09:09.849 --> 09:12.619 at standard depths,as well as in areas 09:12.619 --> 09:15.321 where they observesome unusual features. 09:15.321 --> 09:18.992 >>All right, could youbring her up to 800? 09:18.992 --> 09:20.960 >>NARRATOR: The water samplescollected are then used 09:20.960 --> 09:23.363 for various analyses. 09:23.363 --> 09:27.600 One technique can quickly detectthe presence of hydrocarbons 09:27.600 --> 09:29.769 in the water. 09:29.769 --> 09:31.604 >>The technique is basedon the fluorescence properties 09:31.604 --> 09:33.807 of some chemical compounds. 09:33.807 --> 09:38.578 What we do is we shine light ofdifferent energies on a sample, 09:38.578 --> 09:43.550 and we collect all the emissionat different wavelengths. 09:43.550 --> 09:45.885 This gives usa three-dimensional picture 09:45.885 --> 09:50.490 of the total fluorescenceof the water in our sample. 09:50.490 --> 09:53.893 >>So at this characteristiclevel here, 09:53.893 --> 09:58.031 which is in the ultravioletrange 09:58.031 --> 10:01.234 that's still below the detectionlevel of the human eye, 10:01.234 --> 10:04.571 that's a telltale signof a petroleum signature 10:04.571 --> 10:06.239 in the water. 10:06.239 --> 10:07.941 >>NARRATOR:Samples that test positive 10:07.941 --> 10:09.342 for hydrocarbon presence 10:09.342 --> 10:12.879 are analyzed furtherand fingerprinted 10:12.879 --> 10:17.250 to see if they are from the"Deepwater Horizon" spill site. 10:17.250 --> 10:20.820 Other USF researchers alongon the cruises 10:20.820 --> 10:23.656 analyze water samplesfrom the same sites 10:23.656 --> 10:27.026 to see if they detect toxicity. 10:27.026 --> 10:31.498 To do so, they use two differenttests, or assays. 10:34.801 --> 10:37.170 >>So for this assay,we are using a living organism, 10:37.170 --> 10:40.640 a type of phytoplankton calleddinoflagellate, as an indicator 10:40.640 --> 10:43.710 whether or not there issomething harmful in the water, 10:43.710 --> 10:46.379 something that will negativelyaffect its metabolism. 10:46.379 --> 10:50.517 So these dinoflagellatesbioluminesce, or they glow, 10:50.517 --> 10:54.787 and produce light as partof their natural metabolism. 10:54.787 --> 10:56.689 And when they are stressed, 10:56.689 --> 10:58.992 they will producea lower level of light. 10:58.992 --> 11:00.827 If there is a decreasedlight emitted, 11:00.827 --> 11:02.595 there is something presentin the environment 11:02.595 --> 11:04.164 that is making them unhappy, 11:04.164 --> 11:05.732 whether it be hydrocarbonsor something else. 11:05.732 --> 11:07.901 Essentially, we are lookingfor a correlation 11:07.901 --> 11:10.403 between the toxicity datawe've come up with 11:10.403 --> 11:12.839 and data collected by scientists 11:12.839 --> 11:14.774 that shows the presenceof hydrocarbons. 11:14.774 --> 11:16.676 So if we can correlate toxicity 11:16.676 --> 11:18.044 with the presenceof hydrocarbons, 11:18.044 --> 11:19.479 that would provide evidence 11:19.479 --> 11:22.448 for a biological effectin the environment. 11:25.919 --> 11:28.488 >>NARRATOR: The second test,or assay, uses a bacterium 11:28.488 --> 11:33.660 instead of phytoplanktonto search for toxicity. 11:33.660 --> 11:38.131 >>No one organism reactsto all the toxicants. 11:38.131 --> 11:40.400 What we found was thatthe bacterial assay 11:40.400 --> 11:42.769 was more sensitive to oil. 11:42.769 --> 11:46.372 The dinoflagellate assay wasmore sensitive to the Corexit. 11:46.372 --> 11:47.807 >>NARRATOR:These tests show, 11:47.807 --> 11:50.977 if there is an acutetoxicity present, 11:50.977 --> 11:54.280 that could have an immediateimpact on the ecosystem. 11:54.280 --> 11:58.351 Scientists are also veryconcerned about the impact 11:58.351 --> 12:02.255 that low-level,long-term exposure could have 12:02.255 --> 12:05.391 on marine speciesand ecosystem health. 12:05.391 --> 12:08.261 >>The chronic toxicity,the sub-acute toxicity 12:08.261 --> 12:09.762 we haven't measured, 12:09.762 --> 12:12.932 and we don't know whatthe impact of that's going to be 12:12.932 --> 12:15.401 on the food chain,on fisheries, 12:15.401 --> 12:17.503 and the healthof the Gulf of Mexico. 12:17.503 --> 12:21.207 >>The analogy is you can stickyour nose into a bucket of paint 12:21.207 --> 12:25.111 and you can snifffor a minute and get a headache, 12:25.111 --> 12:26.479 a raging headache, 12:26.479 --> 12:30.216 or you can paint your roomand sleep in the room overnight 12:30.216 --> 12:32.185 and wake upwith the same headache. 12:32.185 --> 12:34.153 So you can havea lower concentration 12:34.153 --> 12:36.322 in the surrounding environment 12:36.322 --> 12:38.558 but be exposed to itfor a longer period of time, 12:38.558 --> 12:41.427 giving the same toxic response. 12:41.427 --> 12:44.230 >>NARRATOR:Another toxicity assay 12:44.230 --> 12:49.869 looks at the potential of toxinsto cause DNA mutations. 12:49.869 --> 12:54.674 Of the water samples collectedin August 2010, 12:54.674 --> 12:57.810 about half weregenetically toxic. 12:57.810 --> 13:01.314 Tests conducted as recentlyas February 2011 13:01.314 --> 13:04.651 continued to findgenetically toxic samples. 13:04.651 --> 13:08.054 >>And that means mutagenic, 13:08.054 --> 13:11.457 or the capability to damage DNAand cause mutations, 13:11.457 --> 13:14.093 and mutations can lead to cancer 13:14.093 --> 13:17.964 and other bad effectsin marine life. 13:17.964 --> 13:20.800 And the other thing aboutDNA-damaging agents is that 13:20.800 --> 13:23.469 it becomes a heritable trait. 13:23.469 --> 13:26.005 If there's a mutationthat's caused, 13:26.005 --> 13:27.540 it can be permanently changed 13:27.540 --> 13:30.209 in that particular breed stockor organism, 13:30.209 --> 13:34.480 so we're very concerned aboutthose types of toxicities. 13:34.480 --> 13:39.752 One of the most susceptibleto genetic toxic materials 13:39.752 --> 13:41.621 are larvae. 13:41.621 --> 13:43.756 And these are organismsthat are just rapidly growing, 13:43.756 --> 13:47.193 rapidly dividing,synthesizing a lot of DNA. 13:47.193 --> 13:48.661 Now, the problem is that 13:48.661 --> 13:51.764 the larvae won't turn upto be adult fish 13:51.764 --> 13:53.666 for maybe three or four years, 13:53.666 --> 13:56.202 so we might not really seethe genetic impact 13:56.202 --> 13:58.571 for a couple years, 13:58.571 --> 14:02.442 and this might manifest itselfin any number of features. 14:06.779 --> 14:10.583 >>NARRATOR: Another groupof USF scientists 14:10.583 --> 14:14.187 is focusing their research onthe impact the spill is having 14:14.187 --> 14:17.457 on the bottom of the food chain. 14:17.457 --> 14:22.261 >>The part of the food webthat our group is targeting 14:22.261 --> 14:24.230 is the lower endof the food web, 14:24.230 --> 14:27.734 which includes the smallmicroscopic plants and animals. 14:27.734 --> 14:30.870 >>NARRATOR: Those microscopicplants and animals 14:30.870 --> 14:33.639 are known as plankton. 14:33.639 --> 14:38.745 >>Which means small organismsadrift with current. 14:38.745 --> 14:42.281 Phytoplankton arethe microscopic plants 14:42.281 --> 14:45.485 that are unicellular plant life. 14:45.485 --> 14:48.588 The zooplankton are the small,microscopic animals. 14:48.588 --> 14:50.590 They range in sizefrom microscopic, 14:50.590 --> 14:52.792 which are the same sizeas the plants, 14:52.792 --> 14:56.963 to individuals likesmall fish larvae, for example, 14:56.963 --> 14:59.265 that you can seewith the naked eye. 14:59.265 --> 15:01.934 And we do a varietyof different analyses 15:01.934 --> 15:04.537 to determinewhat the composition is 15:04.537 --> 15:06.005 of the phytoplanktonand micro-zooplankton, 15:06.005 --> 15:07.273 how many are there, 15:07.273 --> 15:08.808 and how that changesthrough time. 15:08.808 --> 15:11.911 And so what we're tryingto observe is any differences 15:11.911 --> 15:16.115 from a normal,natural variability. 15:20.420 --> 15:22.088 >>NARRATOR: Observingsuch potential changes 15:22.088 --> 15:24.123 is a bit of a challengefor scientists. 15:24.123 --> 15:26.325 >>The Gulf of Mexicohas been understudied, 15:26.325 --> 15:29.929 so we didn't have really goodbaselines for comparison. 15:29.929 --> 15:32.165 >>It's a very complicatedsystem. 15:32.165 --> 15:34.534 I always say the Gulf of Mexico 15:34.534 --> 15:37.203 used to be the RodneyDangerfield of oceans-- 15:37.203 --> 15:38.704 it never got any respect. 15:38.704 --> 15:42.742 >>We need a lot more attentionpaid to establishing 15:42.742 --> 15:47.246 these baselines of all typesso we know what normal is. 15:47.246 --> 15:50.516 >>If we had had years of datato this point where we knew 15:50.516 --> 15:54.220 what the natural variability wasover space and between, 15:54.220 --> 15:56.789 you know, week to week,month to month, year to year, 15:56.789 --> 16:01.127 we would be able to determinemuch more accurately 16:01.127 --> 16:03.563 what the effectsof the BP oil spill were. 16:03.563 --> 16:06.732 >>NARRATOR: Despitesome of the uncertainties, 16:06.732 --> 16:10.002 scientists say they haveobserved a change 16:10.002 --> 16:13.105 in the abundance and healthof plankton, 16:13.105 --> 16:18.611 and they expect to see continuedchanges over the next few years. 16:18.611 --> 16:21.681 An increased mortalityof plankton 16:21.681 --> 16:27.019 could have serious implicationsfor the entire food web. 16:27.019 --> 16:29.989 >>We all fear what we callregime shifts, 16:29.989 --> 16:32.959 when you havea large-scale change 16:32.959 --> 16:35.862 in the dominant animalsof your ecosystem. 16:35.862 --> 16:40.132 It's very stubborn-- once itswitches over to this new order, 16:40.132 --> 16:43.069 it doesn't go back. 16:43.069 --> 16:45.071 And so that would affectfishermen and cultures 16:45.071 --> 16:47.673 all around the Gulf of Mexico 16:47.673 --> 16:49.342 if all of a suddena certain species of animal 16:49.342 --> 16:51.744 that's been harvestedfor generations 16:51.744 --> 16:54.046 has been replacedby another one. 16:54.046 --> 16:56.215 >>I'm veryconcerned about things like 16:56.215 --> 16:57.817 Atlantic bluefin tuna, 16:57.817 --> 17:00.353 which a large fractionof the stock spawns in the area 17:00.353 --> 17:02.321 where there was oilin the water. 17:02.321 --> 17:05.291 >>And so that's a depletedstock as it is, 17:05.291 --> 17:10.029 and so any factor that mightreduce the number of animals 17:10.029 --> 17:13.232 that might recruitto the population is of concern. 17:13.232 --> 17:15.935 One of the things that'skind of a truism 17:15.935 --> 17:19.005 of these big environmentalevents like oil spills is that 17:19.005 --> 17:21.107 we need to expectthe unexpected, 17:21.107 --> 17:24.043 that there may, in fact,be these sub-lethal effects 17:24.043 --> 17:27.346 that will only reveal themselvesover time. 17:27.346 --> 17:29.649 And we certainly saw thatwith "Exxon Valdez," 17:29.649 --> 17:32.618 and it's very likely thatwe'll see that here. 17:32.618 --> 17:35.955 >>In the case of the "ExxonValdez," four years went by 17:35.955 --> 17:40.092 and the local herring stockwas reopened for fishing, 17:40.092 --> 17:43.296 and there was an immediatecollapse in that fishery, 17:43.296 --> 17:48.301 and that stock has not recoveredsince, and decades have passed. 17:48.301 --> 17:51.037 >>NARRATOR:To determine the impact 17:51.037 --> 17:54.507 the Gulf oil spill is havingon fish stocks, 17:54.507 --> 17:59.111 USF researchers are usingan innovative method. 17:59.111 --> 18:01.013 >>We're lookingat the chemistry of otoliths. 18:01.013 --> 18:04.483 Otoliths are ear bonesthat occur in the fish's head. 18:04.483 --> 18:07.587 They're laid down in layerslike an onion or tree rings, 18:07.587 --> 18:10.156 and they incorporatethe chemistry 18:10.156 --> 18:11.490 of the water around them. 18:11.490 --> 18:14.427 So you end upwith a permanent record 18:14.427 --> 18:17.430 of the history of the waterthat the fish was swimming in. 18:17.430 --> 18:20.132 So to get that recordout of the otolith, 18:20.132 --> 18:24.737 we cut very thin sectionsout the middle of the otolith. 18:24.737 --> 18:26.806 And then we polishthose thin sections, 18:26.806 --> 18:30.142 mount them on a slide,bring them to this machine, 18:30.142 --> 18:32.678 and it hasa state of the art laser 18:32.678 --> 18:35.915 that is used to samplethe different types of elements 18:35.915 --> 18:38.317 that are recorded in the rings. 18:38.317 --> 18:40.820 So if this fish were exposedto the oil spill, 18:40.820 --> 18:44.991 you would see unique elementsshowing up in this transect. 18:44.991 --> 18:46.626 So what we're looking for is, 18:46.626 --> 18:49.362 number one, whether or notthe fish was exposed 18:49.362 --> 18:52.365 and, number two,whether or not the fish 18:52.365 --> 18:55.167 experienced slower growth rateafter it was exposed. 18:55.167 --> 18:56.502 Slower growth rate in fish 18:56.502 --> 18:59.472 generally translatesinto higher death rates. 18:59.472 --> 19:03.209 So growth rate is nota trivial thing. 19:03.209 --> 19:04.977 If we see that there wasa reduction in growth rate 19:04.977 --> 19:06.912 associated with exposureto the oil, 19:06.912 --> 19:10.616 then that meanssomething negative 19:10.616 --> 19:13.185 is likely to be influencingthe population. 19:13.185 --> 19:16.155 We have a lot of samplesof important recreational 19:16.155 --> 19:18.924 and commercial species,including red snapper. 19:18.924 --> 19:21.027 We have large predators. 19:21.027 --> 19:22.561 We have small fishfrom the deep ocean 19:22.561 --> 19:24.330 that people generally never see, 19:24.330 --> 19:26.332 even if you spendyour entire life on the Gulf, 19:26.332 --> 19:27.933 things that we've trawled up 19:27.933 --> 19:30.970 from the very deep partof the Gulf of Mexico. 19:30.970 --> 19:32.872 So we have a comprehensivespectrum of species 19:32.872 --> 19:34.407 that we'll be looking at. 19:36.442 --> 19:38.144 >>NARRATOR:Studies suggest 19:38.144 --> 19:41.480 that the oil in the water columnis diluting 19:41.480 --> 19:46.352 and some of its components arebeing broken down by microbes. 19:46.352 --> 19:52.358 As more time passes, experts sayit is becoming more difficult 19:52.358 --> 19:55.261 to find traces of oilin their water samples. 19:55.261 --> 19:58.497 >>The one place that stillseems to be at potential risk 19:58.497 --> 20:00.599 is the sedimentary environment, 20:00.599 --> 20:04.103 both in the shallow but alsoin the deep marine system, 20:04.103 --> 20:06.572 where the plume was,and in that region. 20:06.572 --> 20:09.108 >>NARRATOR:To study the sediments, 20:09.108 --> 20:14.246 experts collect samples witha device called a multicore. 20:17.616 --> 20:22.054 >>There's a central columnthat has eight separate cores 20:22.054 --> 20:26.358 that are set up that, when thedevice hits the sediment floor, 20:26.358 --> 20:30.596 that main column impales itselfinto the sedimentary system, 20:30.596 --> 20:34.433 closing, then,these vacuum-tight seals. 20:34.433 --> 20:38.037 And then the activated samplepulls up, 20:38.037 --> 20:40.740 a bottom arm swingsunderneath the core 20:40.740 --> 20:42.742 and traps the core materialinside 20:42.742 --> 20:44.076 and brings it to the surface. 20:48.280 --> 20:50.316 >>Depth is at 1,002 meters. 21:04.930 --> 21:09.135 >>NARRATOR: Sediment samplesare cut into thin slices 21:09.135 --> 21:14.940 and spun in a centrifuge toseparate the water from the mud. 21:14.940 --> 21:20.246 This water, called pore water,is then analyzed for toxicity 21:20.246 --> 21:23.949 and the presenceof hydrocarbons. 21:23.949 --> 21:26.152 >>This is a shape and a region 21:26.152 --> 21:28.554 that's characteristicof petroleum. 21:28.554 --> 21:33.192 We do need to do furtheranalyses to say, "Oh, this is... 21:33.192 --> 21:38.197 This is exactly one compoundor another compound," 21:38.197 --> 21:41.100 and I'm in the processof doing that right now. 21:41.100 --> 21:44.970 We've got some PAH standards. 21:44.970 --> 21:48.407 PAH stands for polycyclicaromatic hydrocarbons, 21:48.407 --> 21:53.312 and those are some of the mosttoxic compounds 21:53.312 --> 21:56.048 that are in the petroleummixture. 21:56.048 --> 21:59.985 So what I'll do is I'll analyzethose known standards, 21:59.985 --> 22:03.389 and I'll be able to comparethose to what I've seen 22:03.389 --> 22:05.491 in the natural environment. 22:05.491 --> 22:08.227 >>NARRATOR:PAHs are not only 22:08.227 --> 22:11.030 some of the most toxiccomponents of oil, 22:11.030 --> 22:15.634 but they also take a long timeto break down. 22:15.634 --> 22:20.639 To date, USF scientists havefound that pore water samples 22:20.639 --> 22:25.377 from the sediment cores havetested positive for toxicity, 22:25.377 --> 22:29.048 as well as the presenceof hydrocarbons. 22:29.048 --> 22:31.817 Many of those sampleswere taken in an area 22:31.817 --> 22:34.587 known as the De Soto Canyon. 22:34.587 --> 22:36.989 >>We knewfrom prior history that 22:36.989 --> 22:39.158 that was a very important areafor fisheries. 22:39.158 --> 22:42.895 Canyons can also focusthe downward flux of material, 22:42.895 --> 22:44.330 as well. 22:44.330 --> 22:47.166 So we anticipated thatthat might be an area 22:47.166 --> 22:50.302 where we will also see an impacton the seafloor. 22:50.302 --> 22:51.770 >>The sedimentation rates 22:51.770 --> 22:53.772 in those areasin the De Soto Canyon 22:53.772 --> 22:58.344 is about 0.3 millimetersper year-- 0.3-- 22:58.344 --> 23:00.746 so in three years,you get one millimeter. 23:00.746 --> 23:02.615 That's under normal conditions. 23:02.615 --> 23:06.085 What we're recognizing is thatthe sedimentation rate 23:06.085 --> 23:08.654 has increased byabout an order of magnitude. 23:08.654 --> 23:13.492 So now we're looking at threeto ten millimeters per year, 23:13.492 --> 23:16.595 so a significant increasein sedimentation rate. 23:16.595 --> 23:18.364 And the question is why? 23:18.364 --> 23:19.999 And so there are a numberof hypotheses. 23:19.999 --> 23:23.903 The most prevalent one isthe blizzard hypothesis, 23:23.903 --> 23:25.905 and that is thatthe oil droplets, 23:25.905 --> 23:28.340 maybe with the additionof the dispersants, 23:28.340 --> 23:31.577 has lent itselfto a very sticky type material 23:31.577 --> 23:34.613 that aggregates otherbiological material, 23:34.613 --> 23:37.283 and it ballasts itso that it eventually sinks. 23:37.283 --> 23:39.251 And if there's enough of this, 23:39.251 --> 23:43.155 you can actually smotherthe habitat below. 23:43.155 --> 23:46.158 >>NARRATOR: Another theoryon how the sediments 23:46.158 --> 23:49.762 and marine life on the bottom ofthe sea may have been impacted 23:49.762 --> 23:53.666 is known as the bathtub ringhypothesis. 23:53.666 --> 23:57.136 >>The plume, as it impingeson the continental slope, 23:57.136 --> 24:02.508 would leave a bathtub ringof petroleum products. 24:02.508 --> 24:05.411 >>NARRATOR: In some areas,the small creatures that live 24:05.411 --> 24:08.814 on the bottom of the oceanappear impaired or dead, 24:08.814 --> 24:12.785 and scientists say more researchneeds to be done 24:12.785 --> 24:17.856 to understand what is happeningto the ecosystem. 24:17.856 --> 24:23.729 Past oil spills, such asthe "Exxon Valdez" in Alaska 24:23.729 --> 24:26.999 and the Ixtoc spillin the southern Gulf of Mexico 24:26.999 --> 24:29.435 have shown that toxic oil 24:29.435 --> 24:33.138 can persist in the environmentfor decades. 24:33.138 --> 24:35.040 >>The Gulf of Mexico is 24:35.040 --> 24:38.344 one of the three largestoil provenances in the world. 24:38.344 --> 24:41.747 Oil drilling,oil and gas exploration 24:41.747 --> 24:44.683 in the Gulf of Mexicois here to stay. 24:44.683 --> 24:47.252 >>We really needto have this well thought out 24:47.252 --> 24:49.321 in terms of different scenarios, 24:49.321 --> 24:51.690 and that can only occurif you've got research 24:51.690 --> 24:54.526 that's relevant to the differentproblems that might occur. 24:54.526 --> 24:57.296 We need to actually make someserious investments in this 24:57.296 --> 25:00.399 so that the next time around--and there will be a next time-- 25:00.399 --> 25:03.135 that we're not sort of offeringplatitudes 25:03.135 --> 25:04.503 as opposed to actually having 25:04.503 --> 25:08.173 hard quantitative informationavailable. 25:10.976 --> 25:12.644 >>NARRATOR:Many questions remain 25:12.644 --> 25:16.315 about the long-term impactsof this oil spill. 25:16.315 --> 25:19.084 Researchers from the Universityof South Florida 25:19.084 --> 25:22.788 and many other institutionsare doing what they can 25:22.788 --> 25:27.926 to better understand the fullimplications of this disaster. 25:27.926 --> 25:30.362 >>A lot of peopleare working very hard, 25:30.362 --> 25:33.565 doing methodical tasks, 25:33.565 --> 25:37.036 and often it's not until laterthat you realize 25:37.036 --> 25:40.606 the significanceof what you've found. 25:40.606 --> 25:43.475 It'll take many yearsbefore we understand the impact, 25:43.475 --> 25:44.943 and it'll take even longer 25:44.943 --> 25:46.979 before we can put the impactinto context. 25:46.979 --> 25:49.114 Putting the spill into context 25:49.114 --> 25:51.517 is definitely somethingthat will take decades. 26:23.916 --> 26:26.752 >>Major fundingfor this program 26:26.752 --> 26:29.388 was providedby the Batchelor Foundation, 26:29.388 --> 26:32.291 encouraging peopleto preserve and protect 26:32.291 --> 26:36.291 America's underwater resources.