1 00:00:01,725 --> 00:00:03,745 Captioning provided by Extension and Experiment 2 00:00:03,752 --> 00:00:06,417 Station Communications at Oregon State University. 3 00:00:17,014 --> 00:00:18,815 Narrator: An ecosystem. 4 00:00:19,700 --> 00:00:22,831 It's a community of plants and animals. 5 00:00:22,981 --> 00:00:27,656 What we see at the surface is only part of the picture. 6 00:00:28,845 --> 00:00:30,411 In an ecosystem, 7 00:00:30,441 --> 00:00:32,329 everything is related. 8 00:00:32,699 --> 00:00:36,206 And those relationships have evolved over thousands, 9 00:00:36,224 --> 00:00:38,794 even millions of years. 10 00:00:40,247 --> 00:00:43,396 We use the resources of ecosystems. 11 00:00:43,437 --> 00:00:46,054 We need the resources they provide. 12 00:00:46,062 --> 00:00:49,329 And so, we are also linked to the organisms 13 00:00:49,343 --> 00:00:52,243 that call these natural places home. 14 00:00:53,930 --> 00:00:54,935 Over time, 15 00:00:54,962 --> 00:00:57,862 some members of the ecosystem disappear. 16 00:00:58,618 --> 00:01:00,799 And new ones come in. 17 00:01:01,776 --> 00:01:04,189 These are changes that have taken place 18 00:01:04,207 --> 00:01:05,783 at nature's pace. 19 00:01:05,807 --> 00:01:08,419 The system had time to adjust to the loss 20 00:01:08,437 --> 00:01:10,516 and the gain of new species. 21 00:01:10,940 --> 00:01:13,424 That is, until we started looking 22 00:01:13,432 --> 00:01:16,321 at ecosystems with an eye for change, 23 00:01:16,329 --> 00:01:19,669 and began introducing organisms into waterways 24 00:01:19,677 --> 00:01:22,798 beyond their natural range. 25 00:01:29,419 --> 00:01:32,672 Introducing aquatic organisms into new areas 26 00:01:32,682 --> 00:01:36,259 is a widespread phenomenon that takes many forms. 27 00:01:36,265 --> 00:01:39,741 While some species are shipped from distant places, 28 00:01:39,746 --> 00:01:42,509 others are carried to a nearby drainage. 29 00:01:42,540 --> 00:01:45,079 Some are introduced for economic reasons, 30 00:01:45,110 --> 00:01:47,338 some for recreational pursuits, 31 00:01:47,348 --> 00:01:50,815 and some are the unintended result of our activities. 32 00:01:50,828 --> 00:01:52,541 But no matter what the method, 33 00:01:52,559 --> 00:01:54,433 the distance, or the purpose, 34 00:01:54,472 --> 00:01:57,502 a species that gets into a waterway as a result 35 00:01:57,525 --> 00:02:01,204 of human activities is a non-native species, 36 00:02:01,209 --> 00:02:03,554 an aquatic introduction. 37 00:02:08,807 --> 00:02:11,857 The Chinese first introduced aquatic animals. 38 00:02:11,861 --> 00:02:13,674 About 3,000 years ago, 39 00:02:13,679 --> 00:02:16,547 they domesticated the carp and began placing 40 00:02:16,552 --> 00:02:18,894 them into rivers throughout the country. 41 00:02:22,762 --> 00:02:25,234 By the Middle Ages, Asian carp 42 00:02:25,254 --> 00:02:27,237 had been introduced in Europe— 43 00:02:27,250 --> 00:02:29,843 first in monastery ponds where the fish became 44 00:02:29,862 --> 00:02:32,780 a food source for monks who didn't eat red meat, 45 00:02:32,788 --> 00:02:35,699 and eventually into natural waters throughout 46 00:02:35,720 --> 00:02:36,916 the continent. 47 00:02:36,936 --> 00:02:38,452 Across the Atlantic, 48 00:02:38,466 --> 00:02:42,123 it was barely 100 years after Columbus arrived 49 00:02:42,139 --> 00:02:45,196 that the first foreign fish were introduced 50 00:02:45,214 --> 00:02:46,650 to the New World. 51 00:02:46,666 --> 00:02:47,935 Goldfish, 52 00:02:47,947 --> 00:02:49,867 a relative of the Asian carp, 53 00:02:49,881 --> 00:02:52,122 were planted into North American waters 54 00:02:52,140 --> 00:02:54,335 in the mid-1600s. 55 00:02:56,027 --> 00:02:58,408 The first large-scale aquatic introduction 56 00:02:58,427 --> 00:03:01,498 to North America came in 1872. 57 00:03:01,519 --> 00:03:02,948 Again it was the carp, 58 00:03:02,967 --> 00:03:05,131 brought from Germany to Northern California 59 00:03:05,136 --> 00:03:07,348 by a businessman with a dream. 60 00:03:07,366 --> 00:03:10,076 Julius Poppe was an entrepreneur who hoped 61 00:03:10,098 --> 00:03:13,111 to raise carp and sell them across the country. 62 00:03:13,127 --> 00:03:15,926 He was sure Americans would come to love carp 63 00:03:15,936 --> 00:03:17,539 as the Europeans did. 64 00:03:17,554 --> 00:03:20,433 Only five of his fish survived the trip, 65 00:03:20,437 --> 00:03:22,219 but that was all it took. 66 00:03:22,237 --> 00:03:23,450 Carp are hardy, 67 00:03:23,457 --> 00:03:25,833 and these five were ready to breed. 68 00:03:25,837 --> 00:03:27,770 And breed they did. 69 00:03:27,783 --> 00:03:29,047 In no time, 70 00:03:29,065 --> 00:03:31,234 Poppe began selling hundreds of his carp 71 00:03:31,253 --> 00:03:32,952 to farmers everywhere. 72 00:03:33,552 --> 00:03:36,896 Thanks to the railroad and fish transport cars, 73 00:03:36,919 --> 00:03:40,568 carp were soon raised in ponds throughout the country. 74 00:03:40,840 --> 00:03:42,393 But before long, 75 00:03:42,417 --> 00:03:44,959 spring storms and flash floods 76 00:03:44,985 --> 00:03:48,499 washed carp out of their ponds and set them 77 00:03:48,514 --> 00:03:51,608 free in America's rivers and streams. 78 00:03:51,615 --> 00:03:53,940 They adapted quickly to the wild. 79 00:03:53,955 --> 00:03:56,183 It wasn't long before they could be found 80 00:03:56,197 --> 00:03:58,681 in almost any suitable body of water. 81 00:03:58,917 --> 00:04:01,298 But, in less than twenty years, 82 00:04:01,316 --> 00:04:05,684 many saw the carp introductions as a huge mistake. 83 00:04:05,689 --> 00:04:09,721 Americans didn't take to their taste as Europeans did. 84 00:04:09,739 --> 00:04:12,364 Anglers complained the fish were bony 85 00:04:12,372 --> 00:04:13,715 and hard to clean. 86 00:04:13,733 --> 00:04:16,923 And carp were also unpopular for the damage 87 00:04:16,942 --> 00:04:19,643 they did to natural ecosystems. 88 00:04:19,671 --> 00:04:21,594 To feed, 89 00:04:21,598 --> 00:04:25,265 carp suck in a mouthful of mud, insects, clams, 90 00:04:25,280 --> 00:04:27,078 and other invertebrates found along the bottom 91 00:04:27,102 --> 00:04:28,320 of a waterway. 92 00:04:28,343 --> 00:04:30,837 They spit out the mixture so the particles 93 00:04:30,855 --> 00:04:32,016 are suspended, 94 00:04:32,040 --> 00:04:33,781 and then suck in the food. 95 00:04:33,799 --> 00:04:36,715 In the process, they stir up silt and mud, 96 00:04:36,742 --> 00:04:39,586 making the water cloudy and lowering the visibility. 97 00:04:39,604 --> 00:04:42,266 The habitat becomes less suitable for other 98 00:04:42,289 --> 00:04:45,529 fish who need clear water to find their prey. 99 00:04:45,689 --> 00:04:49,358 As the problems created by carp became more apparent, 100 00:04:49,366 --> 00:04:53,254 agencies began looking at ways to get rid of the fish. 101 00:04:53,298 --> 00:04:54,879 In a number of states, 102 00:04:54,895 --> 00:04:56,110 seining, trapping, 103 00:04:56,137 --> 00:04:59,252 and even adding toxins to the system have been 104 00:04:59,269 --> 00:05:01,143 tried with little success. 105 00:05:01,151 --> 00:05:04,589 It seems carp are here to stay. 106 00:05:06,576 --> 00:05:07,765 This practice, 107 00:05:07,783 --> 00:05:10,639 of taking a species and planting it into 108 00:05:10,647 --> 00:05:12,899 an area beyond its normal range, 109 00:05:12,915 --> 00:05:14,725 continues today. 110 00:05:14,786 --> 00:05:18,125 Since the lessons learned from the carp introductions, 111 00:05:18,144 --> 00:05:21,268 it's hoped all introductions are well-studied 112 00:05:21,291 --> 00:05:22,719 and well-planned. 113 00:05:22,765 --> 00:05:25,037 But sometimes they're not. 114 00:05:25,064 --> 00:05:27,606 Sometimes we don't even know we've introduced 115 00:05:27,627 --> 00:05:31,018 an organism until it becomes a nuisance. 116 00:05:33,169 --> 00:05:36,162 Probably the most dramatic example of our time 117 00:05:36,181 --> 00:05:38,500 has been the accidental introduction of 118 00:05:38,514 --> 00:05:39,718 the zebra mussel. 119 00:05:39,771 --> 00:05:42,807 A small mussel from Europe's Caspian Sea, 120 00:05:42,833 --> 00:05:45,126 it most likely arrived here in the ballast 121 00:05:45,161 --> 00:05:46,217 water of a ship. 122 00:05:46,236 --> 00:05:49,372 Since its discovery in Lake St. Clair in 123 00:05:49,391 --> 00:05:51,351 the Great Lakes basin in 1988, 124 00:05:51,367 --> 00:05:53,470 its numbers have exploded. 125 00:05:53,476 --> 00:05:54,757 Within a year, 126 00:05:54,776 --> 00:05:57,860 colonies of 30,000 to 40,000 per square 127 00:05:57,879 --> 00:06:00,090 meter were found in Lake Erie. 128 00:06:00,109 --> 00:06:03,866 By 1994, zebra mussels had spread to all 129 00:06:03,884 --> 00:06:05,513 of the Great Lakes, 130 00:06:05,521 --> 00:06:07,637 throughout the Mississippi Valley, 131 00:06:07,656 --> 00:06:10,420 and east to New York's Hudson River. 132 00:06:10,439 --> 00:06:11,985 And as they've spread, 133 00:06:12,005 --> 00:06:15,173 zebra mussels have left a path of serious problems. 134 00:06:15,190 --> 00:06:17,832 The little organisms can attach themselves 135 00:06:17,871 --> 00:06:19,537 to any solid surface, 136 00:06:19,576 --> 00:06:20,774 including each other. 137 00:06:20,782 --> 00:06:23,503 In some places they've been found in layers 138 00:06:23,525 --> 00:06:25,640 8 to 12 inches thick. 139 00:06:25,652 --> 00:06:28,523 These layers have clogged intake pipes of 140 00:06:28,542 --> 00:06:30,077 industrial facilities, 141 00:06:30,112 --> 00:06:32,979 power plants, and municipal water suppliers. 142 00:06:33,011 --> 00:06:35,545 In the short time they've been in this country, 143 00:06:35,553 --> 00:06:38,130 their damage has cost millions. 144 00:06:38,745 --> 00:06:42,118 The potential ecological impact of zebra mussels 145 00:06:42,133 --> 00:06:44,022 is equally dramatic. 146 00:06:44,041 --> 00:06:47,296 Each mussel filters about a quart of water a day, 147 00:06:47,331 --> 00:06:49,709 feeding on microscopic organisms. 148 00:06:49,728 --> 00:06:52,801 Organisms that are food for small fish who 149 00:06:52,809 --> 00:06:56,169 are eaten by larger fish and eventually humans. 150 00:06:56,191 --> 00:06:58,538 Given their voracious feeding habits, 151 00:06:58,556 --> 00:07:00,471 and their tremendous numbers, 152 00:07:00,476 --> 00:07:03,137 zebra mussels have the potential to alter 153 00:07:03,145 --> 00:07:07,672 entire ecosystems and disrupt aquatic food webs. 154 00:07:08,381 --> 00:07:10,901 While the ballast water introductions are 155 00:07:10,931 --> 00:07:13,851 an unintentional result of human activities, 156 00:07:13,890 --> 00:07:16,331 other organisms are introduced into our 157 00:07:16,345 --> 00:07:18,139 waters on purpose. 158 00:07:18,160 --> 00:07:19,255 (Plane soars by) 159 00:07:19,891 --> 00:07:22,380 Often, the reason is simply to add a species 160 00:07:22,388 --> 00:07:24,821 in hopes it will survive to produce something 161 00:07:24,842 --> 00:07:27,304 that's desirable to a group of people. 162 00:07:27,324 --> 00:07:29,973 However, in the zebra mussel example, 163 00:07:30,003 --> 00:07:32,762 introduced species are not isolated from 164 00:07:32,781 --> 00:07:34,745 the community of plants and animals they 165 00:07:34,767 --> 00:07:36,954 now share a home with. 166 00:07:37,363 --> 00:07:41,963 Stan Gregory: All introductions change communities. 167 00:07:42,706 --> 00:07:45,562 Whether that's bad or good depends upon our 168 00:07:45,579 --> 00:07:48,718 perspective of the function of those communities. 169 00:07:49,333 --> 00:07:50,856 It does bring change. 170 00:07:51,305 --> 00:07:52,451 They are different. 171 00:07:52,477 --> 00:07:54,786 And then the consequences have to be weighed 172 00:07:54,809 --> 00:07:56,910 through time as to how that new community can 173 00:07:56,947 --> 00:07:59,514 function and what that does to the previously 174 00:07:59,532 --> 00:08:01,034 existing community. 175 00:08:02,179 --> 00:08:04,315 Narrator: While we know a community will be 176 00:08:04,322 --> 00:08:06,267 affected by an introduction, 177 00:08:06,293 --> 00:08:08,703 it can be difficult to accurately predict 178 00:08:08,724 --> 00:08:10,575 what those changes will be, 179 00:08:10,580 --> 00:08:13,465 including any potential negative impacts. 180 00:08:14,020 --> 00:08:16,785 Flathead Lake in northwestern Montana is 181 00:08:16,808 --> 00:08:19,487 the largest natural freshwater lake in the 182 00:08:19,520 --> 00:08:21,218 western U.S. 183 00:08:21,225 --> 00:08:22,694 In 1916, 184 00:08:22,707 --> 00:08:25,758 kokanee salmon were introduced for sportfishing. 185 00:08:25,767 --> 00:08:29,024 Their numbers increased dramatically over the years. 186 00:08:29,809 --> 00:08:31,413 Stanford: By the 1950s, 187 00:08:31,434 --> 00:08:33,192 there were so many fish spawning on 188 00:08:33,203 --> 00:08:34,716 the shoreline that, 189 00:08:34,724 --> 00:08:36,979 after they die, 190 00:08:37,010 --> 00:08:39,055 after spawning, 191 00:08:39,072 --> 00:08:41,351 these fish die after spawning, 192 00:08:42,533 --> 00:08:44,962 there were so many dead carcasses on the shoreline 193 00:08:45,007 --> 00:08:47,389 they had to be collected and carried away 194 00:08:47,408 --> 00:08:50,888 in a dump truck in order to make the area 195 00:08:51,640 --> 00:08:54,253 suitable for people to be around. 196 00:08:55,748 --> 00:08:58,510 Narrator: A land-locked form of the red salmon, 197 00:08:58,532 --> 00:09:01,377 kokanee generally lived for three to four years 198 00:09:01,392 --> 00:09:04,105 in the lake and then spawned either along 199 00:09:04,118 --> 00:09:06,697 the shore or up McDonald Creek, 200 00:09:06,701 --> 00:09:09,154 one of the lake's tributary streams. 201 00:09:09,178 --> 00:09:11,489 As the salmon population grew, 202 00:09:11,535 --> 00:09:13,362 so did the number of anglers. 203 00:09:13,415 --> 00:09:15,887 Flathead Lake became one of the most popular 204 00:09:15,907 --> 00:09:17,706 fishing spots in the west. 205 00:09:17,892 --> 00:09:21,382 But the kokanee boom was a phenomenon destined 206 00:09:21,406 --> 00:09:24,597 to change when another non-native species, 207 00:09:24,605 --> 00:09:27,999 the tiny opossum shrimp, or mysis shrimp, 208 00:09:28,014 --> 00:09:31,278 was introduced into the Flathead Lake basin. 209 00:09:31,637 --> 00:09:34,006 Stanford: Mysis shrimp were introduced into 210 00:09:34,029 --> 00:09:37,548 lakes upstream from Flathead Lake where kokanee 211 00:09:37,568 --> 00:09:39,414 were also introduced previously, 212 00:09:39,435 --> 00:09:41,945 in an attempt to elevate the populations 213 00:09:41,952 --> 00:09:44,920 of the kokanee and make a more viable fishery 214 00:09:44,932 --> 00:09:46,706 for people to harvest. 215 00:09:46,713 --> 00:09:47,919 Unfortunately, 216 00:09:47,925 --> 00:09:49,775 water flows downhill, 217 00:09:49,798 --> 00:09:50,859 and gradually, 218 00:09:50,881 --> 00:09:53,667 after a period of several years, 219 00:09:53,673 --> 00:09:56,833 the mysis showed up in Flathead Lake 220 00:09:56,841 --> 00:09:59,186 and established a population here. 221 00:09:59,360 --> 00:10:01,470 And like most exotic species, 222 00:10:01,484 --> 00:10:04,963 this little shrimp became very abundant 223 00:10:04,971 --> 00:10:07,689 in Flathead Lake in a matter of just a few years. 224 00:10:07,706 --> 00:10:12,222 We first found it in the lake around 1981-2, 225 00:10:12,231 --> 00:10:16,392 and by 1984 and -5 the numbers were up 226 00:10:16,416 --> 00:10:19,276 to about 120 mysis per square meter on 227 00:10:19,308 --> 00:10:21,209 the surface of the lake. 228 00:10:21,216 --> 00:10:23,538 So they just exploded in numbers. 229 00:10:26,037 --> 00:10:27,158 Narrator: Meanwhile, 230 00:10:27,158 --> 00:10:29,722 biologists were counting the salmon migrating 231 00:10:29,730 --> 00:10:31,331 up McDonald Creek. 232 00:10:32,887 --> 00:10:34,617 Stanford: Well this is a typical bar 233 00:10:34,639 --> 00:10:36,620 for red salmon to spawn on. 234 00:10:36,648 --> 00:10:37,677 Narrator: In some years, 235 00:10:37,698 --> 00:10:40,164 more than 100,000 salmon made the trip. 236 00:10:40,197 --> 00:10:43,321 The highest number recorded was 400,000. 237 00:10:43,347 --> 00:10:46,561 But in 1987, something went wrong. 238 00:10:46,568 --> 00:10:50,090 Only 330 salmon made it to the creek that year. 239 00:10:50,116 --> 00:10:51,331 The next year, 240 00:10:51,355 --> 00:10:52,847 only 50. 241 00:10:52,855 --> 00:10:55,541 And while anglers had been taking up to 200,000 242 00:10:55,572 --> 00:10:56,904 kokanee a year, 243 00:10:56,912 --> 00:11:01,290 not a single kokanee was caught in 1988 or '89. 244 00:11:01,303 --> 00:11:04,424 The Flathead Lake salmon population crashed. 245 00:11:04,441 --> 00:11:06,051 And it hasn't come back, 246 00:11:06,075 --> 00:11:08,649 despite re-stocking efforts. 247 00:11:12,703 --> 00:11:15,514 University of Montana researchers found two 248 00:11:15,533 --> 00:11:18,349 problems in this complicated situation. 249 00:11:18,385 --> 00:11:19,679 First of all, 250 00:11:19,698 --> 00:11:22,663 kokanee and mysis were not at the same place 251 00:11:22,683 --> 00:11:24,220 at the same time. 252 00:11:24,233 --> 00:11:26,206 Stanford: Kokanee live in the upper layers 253 00:11:26,222 --> 00:11:28,687 of the water column of this big deep lake, 254 00:11:28,708 --> 00:11:31,809 they don't go into the deep layers because 255 00:11:31,827 --> 00:11:33,275 it's too cold for them. 256 00:11:33,299 --> 00:11:35,280 The mysis, on the other hand, 257 00:11:35,301 --> 00:11:38,241 are adapted to living in the deep layers. 258 00:11:39,188 --> 00:11:42,059 We have a layer of Mysis right here, 259 00:11:42,077 --> 00:11:45,111 They were about 68 meters... 260 00:11:45,507 --> 00:11:48,395 Narrator: Mysis do come up to the surface to feed, 261 00:11:48,415 --> 00:11:49,828 but only at night. 262 00:11:49,862 --> 00:11:52,896 And they return to the lake bottom during the day. 263 00:11:52,934 --> 00:11:55,529 But kokanee only feed during the day. 264 00:11:55,556 --> 00:11:58,165 So when it came time for the salmon to eat, 265 00:11:58,185 --> 00:12:00,465 the mysis weren't there. 266 00:12:00,486 --> 00:12:03,613 A second problem was in the food supply. 267 00:12:03,634 --> 00:12:06,065 Kokanee eat zooplankton, 268 00:12:06,070 --> 00:12:08,584 tiny organisms that drift in currents. 269 00:12:08,595 --> 00:12:10,827 And so do mysis. 270 00:12:10,847 --> 00:12:13,070 Stanford: that gave the mysus a distinct 271 00:12:13,080 --> 00:12:14,425 competitive advantage. 272 00:12:14,437 --> 00:12:17,157 Because they could feed on the zooplankton 273 00:12:17,162 --> 00:12:18,935 very effectively, 274 00:12:18,957 --> 00:12:22,186 their population grew to large numbers very quickly, 275 00:12:22,209 --> 00:12:24,348 and almost before we knew it, 276 00:12:24,357 --> 00:12:26,591 they had eaten the entire food supply 277 00:12:26,622 --> 00:12:28,866 of the kokanee salmon. 278 00:12:28,892 --> 00:12:31,468 Narrator: The effects of the shrimp introduction 279 00:12:31,487 --> 00:12:33,777 were felt throughout the ecosystem. 280 00:12:33,786 --> 00:12:36,431 Flathead Lake and its tributaries had become 281 00:12:36,456 --> 00:12:38,907 a gathering place for a variety of animals 282 00:12:38,923 --> 00:12:41,084 who had one thing in common: 283 00:12:41,109 --> 00:12:42,660 they ate salmon. 284 00:12:42,680 --> 00:12:45,405 Bald eagles were among the most prominent. 285 00:12:45,450 --> 00:12:47,486 Hundreds gathered along McDonald Creek 286 00:12:47,505 --> 00:12:49,632 to eat dead and dying salmon. 287 00:12:51,372 --> 00:12:53,820 But when the kokanee population collapsed, 288 00:12:53,828 --> 00:12:56,489 the animals who had come to depend on salmon 289 00:12:56,494 --> 00:12:59,167 as a source of protein either disappeared 290 00:12:59,188 --> 00:13:00,945 or declined dramatically. 291 00:13:08,176 --> 00:13:10,905 Most introductions are made with the best 292 00:13:10,929 --> 00:13:12,177 of intentions. 293 00:13:12,200 --> 00:13:14,995 Most are based on perceived social or economic 294 00:13:15,006 --> 00:13:16,420 needs of the day. 295 00:13:16,441 --> 00:13:17,613 And sometimes, 296 00:13:17,618 --> 00:13:19,692 well-planned and well-run introductions 297 00:13:19,699 --> 00:13:21,705 can make a positive difference. 298 00:13:22,099 --> 00:13:25,142 Some of the benefits include an increased 299 00:13:25,169 --> 00:13:26,426 food supply... 300 00:13:28,202 --> 00:13:29,620 recreation .... 301 00:13:29,654 --> 00:13:31,175 and pest control. 302 00:13:31,481 --> 00:13:32,914 But in some cases, 303 00:13:32,929 --> 00:13:35,276 the needs of the past aren't necessarily 304 00:13:35,294 --> 00:13:37,468 the needs of the present or the future. 305 00:13:37,504 --> 00:13:39,436 And what we're learning is that while 306 00:13:39,459 --> 00:13:41,452 the intentions of past introductions 307 00:13:41,471 --> 00:13:42,619 were well meaning, 308 00:13:42,630 --> 00:13:46,161 non-native organisms can create unforeseen 309 00:13:46,170 --> 00:13:49,483 complications in natural ecosystems. 310 00:13:51,800 --> 00:13:53,525 In one type of introduction, 311 00:13:53,547 --> 00:13:56,240 a species is added to a community in the hopes that 312 00:13:56,246 --> 00:13:59,361 it will control or eliminate an undesirable species. 313 00:13:59,393 --> 00:14:03,046 It's a type of introduction called biological control. 314 00:14:03,068 --> 00:14:06,722 For example, mosquitofish are used as a biological 315 00:14:06,734 --> 00:14:09,750 control species in rice fields where mosquitoes 316 00:14:09,771 --> 00:14:11,558 can be a serious health problem. 317 00:14:11,585 --> 00:14:13,909 Joe Cech: Mosquitofish are not a cure-all, it's 318 00:14:13,930 --> 00:14:15,157 not a panacea, 319 00:14:15,614 --> 00:14:17,646 it's all effective tool, 320 00:14:17,676 --> 00:14:19,533 and if used properly, 321 00:14:19,541 --> 00:14:21,862 it can be a very effective biological control 322 00:14:21,882 --> 00:14:23,425 of mosquitos, 323 00:14:23,783 --> 00:14:26,486 but like all introduced species we have to be 324 00:14:26,499 --> 00:14:29,976 very careful and very concerned that we use 325 00:14:29,984 --> 00:14:31,299 it in the right way. 326 00:14:31,828 --> 00:14:33,307 Narrator: In the desert Southwest, 327 00:14:33,325 --> 00:14:37,283 mosquitofish introductions threaten native species. 328 00:14:37,319 --> 00:14:38,942 Along the Colorado River, 329 00:14:38,967 --> 00:14:41,974 the Gila topminnow flourished until mosquitofish 330 00:14:41,991 --> 00:14:43,202 were introduced. 331 00:14:43,242 --> 00:14:45,932 The topminnow population is now on the brink 332 00:14:45,952 --> 00:14:47,127 of extinction. 333 00:14:47,145 --> 00:14:49,113 One reason for the decline... 334 00:14:49,135 --> 00:14:51,908 mosquitofish eat young topminnows. 335 00:14:51,929 --> 00:14:53,389 In some areas, 336 00:14:53,395 --> 00:14:55,702 topminnows have disappeared within two years 337 00:14:55,728 --> 00:14:57,857 of a mosquitofish introduction. 338 00:14:59,588 --> 00:15:01,835 It's a similar story in Arizona. 339 00:15:01,840 --> 00:15:04,638 Mosquitofish are one of the several species that 340 00:15:04,656 --> 00:15:07,658 have been introduced into desert pupfish habitats. 341 00:15:07,690 --> 00:15:09,463 Since these introductions, 342 00:15:09,489 --> 00:15:12,854 the number of pupfishes has rapidly declined. 343 00:15:12,884 --> 00:15:14,178 Ironically, 344 00:15:14,204 --> 00:15:16,865 some of the species mosquitofish are helping 345 00:15:16,887 --> 00:15:20,351 to eliminate also eat mosquito larvae. 346 00:15:20,370 --> 00:15:23,690 Both Gila topminnows and desert pupfishes, 347 00:15:23,707 --> 00:15:24,900 if left alone, 348 00:15:24,909 --> 00:15:27,384 are quite effective at mosquito control in 349 00:15:27,402 --> 00:15:29,513 their natural habitats. 350 00:15:31,393 --> 00:15:33,939 Another reason for introducing species beyond 351 00:15:33,945 --> 00:15:37,068 their natural range is to develop or improve 352 00:15:37,083 --> 00:15:38,687 a fishery. 353 00:15:38,711 --> 00:15:41,146 Either the game species themselves or bait 354 00:15:41,165 --> 00:15:43,030 for game species. 355 00:15:44,984 --> 00:15:48,862 Today, anglers may try their luck on bass, 356 00:15:48,902 --> 00:15:50,336 crappie, catfish, 357 00:15:50,360 --> 00:15:51,623 and many others, 358 00:15:51,654 --> 00:15:54,632 hundreds of miles from their native streams. 359 00:15:54,639 --> 00:15:55,858 In fact, 360 00:15:55,873 --> 00:15:58,487 more than one-quarter of all of the freshwater 361 00:15:58,507 --> 00:16:00,838 fish caught by anglers in the United States 362 00:16:00,852 --> 00:16:02,880 are not native. 363 00:16:03,260 --> 00:16:05,272 But what are the effects of these introductions 364 00:16:05,301 --> 00:16:07,220 on the receiving ecosystems? 365 00:16:07,254 --> 00:16:10,355 Introduced species interact with natives in 366 00:16:10,377 --> 00:16:11,776 a number of ways. 367 00:16:11,787 --> 00:16:14,574 An introduced species may breed with a related 368 00:16:14,596 --> 00:16:16,106 native species. 369 00:16:16,112 --> 00:16:18,409 Apache trout were abundant in the streams 370 00:16:18,426 --> 00:16:20,348 of Arizona's White Mountains. 371 00:16:20,363 --> 00:16:22,732 But when introduced rainbow trout bred with 372 00:16:22,753 --> 00:16:24,227 the native Apache trout, 373 00:16:24,249 --> 00:16:26,160 the native population plummeted. 374 00:16:26,181 --> 00:16:28,277 Hybridization can affect the fitness 375 00:16:28,301 --> 00:16:29,925 of the native species. 376 00:16:29,946 --> 00:16:31,876 It has a more difficult time coping with 377 00:16:31,899 --> 00:16:33,409 environmental stresses. 378 00:16:33,432 --> 00:16:35,291 In the case of the Apache trout, 379 00:16:35,326 --> 00:16:38,762 where once they occupied 600 miles of streams, 380 00:16:38,779 --> 00:16:41,949 today they can be found on only 30 miles. 381 00:16:43,937 --> 00:16:46,011 California's state fish, 382 00:16:46,051 --> 00:16:47,344 the golden trout, 383 00:16:47,363 --> 00:16:49,943 nearly disappeared when brown trout made their 384 00:16:49,974 --> 00:16:52,037 way into the Kern River system. 385 00:16:52,045 --> 00:16:54,116 The golden trout couldn't compete with 386 00:16:54,135 --> 00:16:55,626 the larger browns. 387 00:16:55,658 --> 00:16:58,302 And they were easy prey for the newcomer. 388 00:16:58,893 --> 00:17:02,529 Largemouth bass are another predatory game fish 389 00:17:02,543 --> 00:17:04,574 that can impact a native species. 390 00:17:04,615 --> 00:17:07,175 Largemouth bass are native to the Mississippi 391 00:17:07,204 --> 00:17:09,286 River drainage and the southeast, 392 00:17:09,308 --> 00:17:11,586 but they've been stocked outside their native 393 00:17:11,620 --> 00:17:14,918 range for sportfishing more than any species 394 00:17:14,967 --> 00:17:17,021 except perhaps the rainbow trout. 395 00:17:17,053 --> 00:17:20,712 Bass are a great fighting fish and fun to catch. 396 00:17:20,724 --> 00:17:23,119 But that aggressive instinct means trouble 397 00:17:23,164 --> 00:17:25,864 for native organisms that haven't evolved 398 00:17:25,897 --> 00:17:27,835 to deal with this newcomer. 399 00:17:27,850 --> 00:17:30,434 Bass are good predators and competitors 400 00:17:30,458 --> 00:17:32,727 and their introductions have been linked 401 00:17:32,756 --> 00:17:35,710 to the decline of many fish now listed 402 00:17:35,742 --> 00:17:37,524 as threatened or endangered. 403 00:17:37,562 --> 00:17:39,146 Historically, 404 00:17:39,156 --> 00:17:42,706 fishery managers have given people what they wanted: 405 00:17:42,743 --> 00:17:45,329 they've stocked and restocked ecosystems 406 00:17:45,346 --> 00:17:47,144 with the desired species. 407 00:17:47,583 --> 00:17:51,607 But success has often led to increased expectations 408 00:17:51,627 --> 00:17:53,669 for more and more fish. 409 00:17:53,678 --> 00:17:55,987 Yet, today we understand that some 410 00:17:55,995 --> 00:17:58,992 of these introductions have led to a decline, 411 00:17:59,026 --> 00:18:01,879 and in some cases even a complete loss, 412 00:18:01,897 --> 00:18:03,397 of a native species. 413 00:18:03,420 --> 00:18:06,375 And the loss of even a single species can 414 00:18:06,381 --> 00:18:07,741 make a difference. 415 00:18:07,760 --> 00:18:09,920 Stan Gregory: It's important to have many 416 00:18:09,933 --> 00:18:11,420 different life forms. 417 00:18:11,447 --> 00:18:14,520 Not only for the multitude of functions that 418 00:18:14,561 --> 00:18:15,733 they provide, 419 00:18:15,754 --> 00:18:18,938 but also for the functions that they provide 420 00:18:18,972 --> 00:18:20,669 that we aren't aware of. 421 00:18:21,361 --> 00:18:25,374 We don't know everything about our world 422 00:18:25,385 --> 00:18:27,977 and we don't know everything that these species 423 00:18:27,994 --> 00:18:29,252 provide for us. 424 00:18:29,274 --> 00:18:30,525 And, 425 00:18:30,545 --> 00:18:31,865 actually, there are probably 426 00:18:31,898 --> 00:18:33,500 organisms in the environment 427 00:18:33,534 --> 00:18:37,298 that are vital to our very existence. 428 00:18:39,762 --> 00:18:42,700 We know that natural ecosystems support human 429 00:18:42,725 --> 00:18:45,314 life by providing purified air, 430 00:18:45,328 --> 00:18:48,573 fresh water, soil production, waste disposal, 431 00:18:48,581 --> 00:18:50,779 a supply of nutrients and energy, 432 00:18:50,803 --> 00:18:53,319 and the high quality of our atmosphere. 433 00:18:53,356 --> 00:18:56,047 So while it may be tempting to add our favorite 434 00:18:56,072 --> 00:18:58,579 game species to waterways everywhere, 435 00:18:58,587 --> 00:19:01,229 we don't have a clear understanding of how 436 00:19:01,251 --> 00:19:03,926 our actions will change ecosystems that all 437 00:19:03,948 --> 00:19:05,649 living organisms, 438 00:19:05,669 --> 00:19:08,262 including humans depend upon. 439 00:19:14,194 --> 00:19:17,265 Direct introductions aren't the only way 440 00:19:17,289 --> 00:19:20,343 non-native species enter our waterways. 441 00:19:20,364 --> 00:19:23,246 Some organisms find their way by escaping 442 00:19:23,276 --> 00:19:26,285 from holding ponds or aquaculture facilities. 443 00:19:26,304 --> 00:19:29,117 One escape route is to ride on the crest 444 00:19:29,150 --> 00:19:31,189 of a storm or flood. 445 00:19:31,499 --> 00:19:33,820 Dennis Lassuy: As we saw very plainly from 446 00:19:33,841 --> 00:19:37,425 Hurricane Andrew and the recent Mississippi river floods, 447 00:19:37,449 --> 00:19:40,062 things don't always stay where you think 448 00:19:40,082 --> 00:19:42,002 they're going to stay or where you want them to stay. 449 00:19:42,670 --> 00:19:45,341 Narrator: Some species escape by swimming through 450 00:19:45,352 --> 00:19:48,301 unscreened pipes in an aquaculture facility... 451 00:19:48,310 --> 00:19:50,863 or during transport... 452 00:19:50,885 --> 00:19:53,075 and sometimes they have been mixed up 453 00:19:53,097 --> 00:19:55,912 with other species being removed from a pond. 454 00:19:56,685 --> 00:19:58,668 Tilapia, for example, 455 00:19:58,687 --> 00:20:01,734 are native to Africa and parts of the Middle East. 456 00:20:01,752 --> 00:20:04,734 They were originally introduced into North America 457 00:20:04,754 --> 00:20:06,764 as aquarium pets. 458 00:20:06,787 --> 00:20:10,556 Today, the tasty fish are grown commercially for food. 459 00:20:10,581 --> 00:20:13,896 But Tilapia have escaped from holding facilities 460 00:20:13,918 --> 00:20:16,671 and entered natural waters many times. 461 00:20:16,701 --> 00:20:19,236 In warm water states like California, 462 00:20:19,256 --> 00:20:21,563 Arizona, Florida, and Texas, 463 00:20:21,590 --> 00:20:25,095 escapees have successfully adapted to the wild. 464 00:20:25,545 --> 00:20:28,285 Some Tilapia species are very aggressive 465 00:20:28,316 --> 00:20:30,438 and compete with native fish for spawning 466 00:20:30,471 --> 00:20:32,229 sites and space. 467 00:20:32,248 --> 00:20:35,537 They may dig holes to spawn and in the process 468 00:20:35,559 --> 00:20:39,258 uproot plants and increase the silt in the river 469 00:20:39,279 --> 00:20:41,565 which can destroy the nests of other fish 470 00:20:41,589 --> 00:20:43,281 and lower the visibility. 471 00:20:43,326 --> 00:20:44,953 Adding to all this, 472 00:20:44,990 --> 00:20:47,882 certain Tilapia species can breed every month. 473 00:20:47,904 --> 00:20:50,361 And because the parents guard them, 474 00:20:50,387 --> 00:20:52,829 the young have a high chance of survival, 475 00:20:52,851 --> 00:20:55,777 resulting in explosive populations. 476 00:20:56,386 --> 00:20:59,110 Many aquaculture facilities are careful 477 00:20:59,148 --> 00:21:01,937 and follow precautions to prevent species 478 00:21:01,964 --> 00:21:04,886 from escaping and entering adjacent waterways. 479 00:21:04,894 --> 00:21:07,800 If all facilities used the same care, 480 00:21:07,823 --> 00:21:10,412 the problem of species entering natural 481 00:21:10,425 --> 00:21:13,414 ecosystems as escapees could be virtually 482 00:21:13,435 --> 00:21:14,766 eliminated. 483 00:21:19,116 --> 00:21:23,204 Often established non-native species are organisms 484 00:21:23,226 --> 00:21:25,489 imported for the aquarium trade. 485 00:21:25,508 --> 00:21:28,861 Some have been released by home aquarium owners. 486 00:21:29,272 --> 00:21:31,157 Mother: "Kids Just dump that fish" 487 00:21:31,404 --> 00:21:33,607 Narrator: Although people's intentions may have 488 00:21:33,623 --> 00:21:35,445 been good when they released their pets, 489 00:21:35,472 --> 00:21:37,804 these introductions haven't been without 490 00:21:37,825 --> 00:21:39,403 their adverse affects. 491 00:21:39,422 --> 00:21:41,165 Goldfish, for example, 492 00:21:41,185 --> 00:21:43,093 have been found in the waterways of nearly 493 00:21:43,116 --> 00:21:44,613 every state in the Union. 494 00:21:44,624 --> 00:21:46,843 But the pretty little fish can revert to their 495 00:21:46,894 --> 00:21:50,464 wild state and develop voracious appetites. 496 00:21:50,486 --> 00:21:52,610 Feeding mostly on aquatic plants, 497 00:21:52,630 --> 00:21:54,870 goldfish can remove significant amounts 498 00:21:54,892 --> 00:21:56,171 of vegetation. 499 00:21:56,193 --> 00:21:58,081 They increase turbidity and contribute to 500 00:21:58,097 --> 00:22:01,458 the decline of invertebrates living in a community. 501 00:22:02,237 --> 00:22:05,345 Introduced plants can also pose problems. 502 00:22:05,354 --> 00:22:07,926 Hydrilla is an aquarium plant that was 503 00:22:07,931 --> 00:22:10,746 apparently introduced in Florida presumably 504 00:22:10,769 --> 00:22:13,762 by individuals cleaning out their home aquariums. 505 00:22:13,797 --> 00:22:15,227 Native to Asia, 506 00:22:15,244 --> 00:22:17,660 Hydrilla flourishes in the wild. 507 00:22:17,687 --> 00:22:19,046 Once established, 508 00:22:19,068 --> 00:22:20,882 Hydrilla grows quickly. 509 00:22:20,887 --> 00:22:22,658 The plant has taken over 90 percent 510 00:22:22,687 --> 00:22:24,060 of this Florida lake, 511 00:22:24,089 --> 00:22:26,335 and covers large areas of other lakes 512 00:22:26,364 --> 00:22:27,427 in the region. 513 00:22:27,437 --> 00:22:30,072 It clogs waterways and has become a nuisance 514 00:22:30,093 --> 00:22:31,564 to navigation. 515 00:22:31,588 --> 00:22:32,998 Since its introduction, 516 00:22:33,024 --> 00:22:35,528 Hydrilla has spread throughout the southeast 517 00:22:35,548 --> 00:22:39,389 and beyond to California, Iowa, and Virginia. 518 00:22:39,412 --> 00:22:43,576 Hiram Li: The reason why exotic species take 519 00:22:43,606 --> 00:22:48,392 off and explode is because they come over 520 00:22:48,419 --> 00:22:52,329 without the system that provides the natural 521 00:22:52,350 --> 00:22:55,123 checks and balances on population growth. 522 00:22:55,151 --> 00:22:56,626 In other words, 523 00:22:56,666 --> 00:23:00,656 these species have adapted to predators, 524 00:23:00,677 --> 00:23:02,319 competitors, 525 00:23:02,331 --> 00:23:05,650 and diseases in another ecosystem. 526 00:23:05,670 --> 00:23:07,742 And when they're transferred to a new one, 527 00:23:07,766 --> 00:23:10,136 the rules of the game are different. 528 00:23:10,159 --> 00:23:11,748 As a matter of fact, 529 00:23:11,769 --> 00:23:15,220 it may be that the new ecosystem doesn't 530 00:23:15,256 --> 00:23:19,516 have a way to check its population growth. 531 00:23:19,524 --> 00:23:21,136 And when that happens, 532 00:23:21,144 --> 00:23:23,872 the aliens become pests. 533 00:23:26,907 --> 00:23:29,288 Narrator: Bait bucket introductions are another 534 00:23:29,312 --> 00:23:31,581 way individuals have transplanted fish 535 00:23:31,597 --> 00:23:33,598 into America's waterways. 536 00:23:38,755 --> 00:23:41,707 An end-of-the-day bait release is presumably 537 00:23:41,740 --> 00:23:43,843 how red shiners showed up in 538 00:23:43,863 --> 00:23:45,513 Nevada's Lake Mead. 539 00:23:45,521 --> 00:23:47,837 The red shiner is a popular bait fish 540 00:23:47,857 --> 00:23:49,394 native to the northeast, 541 00:23:49,412 --> 00:23:52,169 but sold as live bait in some areas of the west. 542 00:23:52,192 --> 00:23:53,689 Once in the lake, 543 00:23:53,710 --> 00:23:56,544 the red shiners traveled up into the Virgin River. 544 00:23:56,564 --> 00:23:59,625 And with the shiner came a parasite. 545 00:23:59,643 --> 00:24:02,253 The Asian tapeworm found its way 546 00:24:02,260 --> 00:24:05,065 to North America when Asian grass carp 547 00:24:05,087 --> 00:24:06,161 were introduced. 548 00:24:06,184 --> 00:24:08,178 And while shiners have been able to adapt 549 00:24:08,197 --> 00:24:09,965 to the effects of the tapeworm, 550 00:24:09,985 --> 00:24:12,517 the native species in the Virgin River have not. 551 00:24:12,536 --> 00:24:15,377 The woundfin minnow in particular is now 552 00:24:15,422 --> 00:24:18,248 an endangered species partly because it's 553 00:24:18,269 --> 00:24:20,122 not able to deal with the effects 554 00:24:20,139 --> 00:24:21,908 of the Asian tapeworm. 555 00:24:25,228 --> 00:24:27,596 At Klamath Lake in southern Oregon, 556 00:24:27,640 --> 00:24:30,228 Oregon State University researchers are 557 00:24:30,259 --> 00:24:32,326 monitoring another bait species, 558 00:24:32,391 --> 00:24:33,916 the fathead minnow. 559 00:24:33,947 --> 00:24:36,900 Dave Simon: The fathead minnows are a species 560 00:24:36,908 --> 00:24:39,769 of the family cyprinidae which are native 561 00:24:39,812 --> 00:24:41,608 to the eastern and midwest states of 562 00:24:41,659 --> 00:24:43,264 the United States. 563 00:24:43,772 --> 00:24:47,039 And they've been brought out west as people 564 00:24:47,074 --> 00:24:48,138 moved out west, 565 00:24:48,167 --> 00:24:51,019 either for use in fishing as bait fish, 566 00:24:51,044 --> 00:24:54,380 or to feed the fish like largemouth bass 567 00:24:54,400 --> 00:24:55,935 and crappie that they brought out to raise 568 00:24:55,982 --> 00:24:57,748 themselves from the Midwest. 569 00:24:58,562 --> 00:25:01,383 They were first captured in Oregon in the late 70's 570 00:25:01,391 --> 00:25:03,355 in the Klamath River south of the city 571 00:25:03,376 --> 00:25:04,827 of Klamath Falls. 572 00:09:51,591 --> 00:25:07,585 And they were first collected in 1982 573 00:25:07,593 --> 00:25:09,149 here in Upper Klamath Lake 574 00:25:09,169 --> 00:25:11,161 by Oregon Department of Fish and Wildlife. 575 00:25:12,324 --> 00:25:14,381 Since 1982, 576 00:25:14,389 --> 00:25:16,428 they've become the most abundant fish 577 00:25:16,455 --> 00:25:17,738 in Upper Klamath Lake. 578 00:25:17,759 --> 00:25:19,086 Narrator: Not only are the number 579 00:25:19,106 --> 00:25:20,598 of minnows increasing, 580 00:25:20,606 --> 00:25:23,335 they're also spreading to other waterways, 581 00:25:23,343 --> 00:25:25,843 leaving researchers wondering what the effect 582 00:25:25,859 --> 00:25:28,515 will be on two native suckers. 583 00:25:28,544 --> 00:25:30,940 Dave Simon: I've seen a lot of larval suckers 584 00:25:30,971 --> 00:25:32,451 Some laboratory experiments 585 00:25:32,474 --> 00:25:34,669 by some local biologists have indicated that, 586 00:25:34,688 --> 00:25:36,595 at least under laboratory conditions, 587 00:25:36,612 --> 00:25:38,990 the fathead minnows will attack 588 00:25:39,013 --> 00:25:41,079 and kill and eat larval suckers. 589 00:25:41,104 --> 00:25:43,667 Whether that happens in the wild we don't 590 00:25:43,699 --> 00:25:44,936 know the answer to that yet. 591 00:25:44,974 --> 00:25:46,768 Narrator: But one thing seems clear. 592 00:25:46,789 --> 00:25:49,405 Once an introduced species establishes 593 00:25:49,428 --> 00:25:51,481 a successful breeding population 594 00:25:51,510 --> 00:25:53,105 in a new ecosystem, 595 00:25:53,127 --> 00:25:55,465 there's almost no way to get rid of it. 596 00:25:55,492 --> 00:25:56,827 And, as we've seen, 597 00:25:56,860 --> 00:25:59,930 introductions often threaten the cornerstone 598 00:25:59,945 --> 00:26:01,377 of an ecosystem... 599 00:26:01,398 --> 00:26:03,143 biodiversity. 600 00:26:03,819 --> 00:26:05,629 Mario Salazi: It's like the analogy of 601 00:26:05,651 --> 00:26:08,408 the watchmaker and the person who tinkers 602 00:26:08,419 --> 00:26:09,724 with the watch. 603 00:26:09,742 --> 00:26:11,995 If you lose parts of the watch, 604 00:26:12,025 --> 00:26:13,960 the watch won't work anymore. 605 00:26:13,993 --> 00:26:15,788 And with the ecosystem, 606 00:26:15,810 --> 00:26:17,382 it's the same way. 607 00:26:17,415 --> 00:26:19,187 All of the parts are important. 608 00:26:19,225 --> 00:26:22,115 And for the whole ecosystem to function, 609 00:26:22,147 --> 00:26:23,961 it needs all of its parts. 610 00:26:25,972 --> 00:26:28,646 Narrator: The story of aquatic introductions 611 00:26:28,666 --> 00:26:29,896 isn't simple. 612 00:26:32,166 --> 00:26:33,574 There are benefits. 613 00:26:34,532 --> 00:26:36,317 There are costs. 614 00:26:38,374 --> 00:26:41,647 And there are impacts that we don't yet understand. 615 00:26:44,511 --> 00:26:47,219 The aim in aquatic management is not to try 616 00:26:47,237 --> 00:26:49,406 and return to the pristine environments 617 00:26:49,420 --> 00:26:51,829 that existed 500 years ago. 618 00:26:51,867 --> 00:26:53,998 We can't undo past mistakes. 619 00:26:54,654 --> 00:26:57,858 But by carefully researching proposed introductions, 620 00:26:57,879 --> 00:26:59,833 we can better understand the system 621 00:26:59,870 --> 00:27:02,053 and the species we want to introduce. 622 00:27:02,073 --> 00:27:04,936 We can evaluate potential impacts and benefits 623 00:27:04,976 --> 00:27:06,448 of the introduction, 624 00:27:06,482 --> 00:27:08,316 both short- and long-term. 625 00:27:08,340 --> 00:27:11,375 Only then can we make informed decisions 626 00:27:11,391 --> 00:27:13,492 about non-native species.