1
00:00:00,110 --> 00:00:05,100
Wasted food is a big problem. Every year

2
00:00:03,060 --> 00:00:06,870
we waste 1.6 billion tons of food

3
00:00:05,100 --> 00:00:08,670
globally. But with every bite we don't

4
00:00:06,870 --> 00:00:10,980
eat we're not just discarding food

5
00:00:08,670 --> 00:00:12,690
we're also wasting the land, water, and

6
00:00:10,980 --> 00:00:14,639
energy resources that went into

7
00:00:12,690 --> 00:00:16,560
producing it. Today wasted food has

8
00:00:14,639 --> 00:00:18,779
become an international humanitarian and

9
00:00:16,560 --> 00:00:20,880
ecological crisis making headlines all

10
00:00:18,779 --> 00:00:22,400
over the world. But what does this have

11
00:00:20,880 --> 00:00:25,109
anything to do with endangered trout?

12
00:00:22,400 --> 00:00:27,080
Steelhead trout, a once abundant species

13
00:00:25,109 --> 00:00:29,310
native to Monterey Bay California,

14
00:00:27,080 --> 00:00:31,589
virtually disappeared in the last 50

15
00:00:29,310 --> 00:00:33,629
years. Populations declined as much as

16
00:00:31,590 --> 00:00:35,750
90% and it quickly became protected

17
00:00:33,630 --> 00:00:37,800
under the Endangered Species Act

18
00:00:35,750 --> 00:00:38,910
Conservation ecologists initially

19
00:00:37,800 --> 00:00:41,010
believed that the trout were threatened

20
00:00:38,910 --> 00:00:42,120
by the San Clemente Dam which prevented

21
00:00:41,010 --> 00:00:44,640
the adults from reaching their breeding

22
00:00:42,120 --> 00:00:47,129
ground and so in 2015 the dam was

23
00:00:44,640 --> 00:00:48,840
removed. The dam's demolition was the

24
00:00:47,129 --> 00:00:51,510
largest dam removal project in

25
00:00:48,840 --> 00:00:53,010
California's history and was considered

26
00:00:51,510 --> 00:00:56,039
a monumental victory for

27
00:00:53,010 --> 00:00:57,360
conservationists. However it did not

28
00:00:56,039 --> 00:00:59,640
create the rebound effect that

29
00:00:57,360 --> 00:01:01,170
scientists had predicted. A group of UC

30
00:00:59,640 --> 00:01:02,789
Santa Cruz researchers began to

31
00:01:01,170 --> 00:01:04,619
investigate and later that year they

32
00:01:02,789 --> 00:01:05,939
published a study that demonstrated a

33
00:01:04,619 --> 00:01:07,500
negative correlation between the

34
00:01:05,939 --> 00:01:09,658
population of steel heads and one of

35
00:01:07,500 --> 00:01:11,939
their natural predators: the Western gull.

36
00:01:09,659 --> 00:01:14,130
Before wasted food became abundant in

37
00:01:11,939 --> 00:01:15,630
the ecosystem, the populations of Western

38
00:01:14,130 --> 00:01:17,310
gulls and steelhead trout kept each

39
00:01:15,630 --> 00:01:18,210
other in check and remained at about the

40
00:01:17,310 --> 00:01:21,030
same level over time

41
00:01:18,210 --> 00:01:22,979
despite periodic fluctuations. This type

42
00:01:21,030 --> 00:01:25,430
of relationship is what ecologist call a

43
00:01:22,979 --> 00:01:27,509
negative feedback loop.

44
00:01:25,430 --> 00:01:28,979
Whenever trout were plentiful the

45
00:01:27,509 --> 00:01:30,930
Western gull population would gorge

46
00:01:28,979 --> 00:01:32,429
itself and grow in size until it began

47
00:01:30,930 --> 00:01:34,820
to eat fish faster than they could

48
00:01:32,430 --> 00:01:34,820
reproduce.

49
00:01:35,150 --> 00:01:40,229
The decreasing fish caused a scarcity of

50
00:01:38,189 --> 00:01:43,439
prey for gulls which push their numbers

51
00:01:40,229 --> 00:01:44,939
back down and once there were fewer

52
00:01:43,439 --> 00:01:46,830
gulls around to eat them the predation

53
00:01:44,939 --> 00:01:48,059
pressure decreased on the trout and the

54
00:01:46,830 --> 00:01:49,970
population would rebound

55
00:01:48,060 --> 00:01:52,530
[Music]

56
00:01:49,970 --> 00:01:53,940
This meant that prey for gulls became

57
00:01:52,530 --> 00:01:57,270
plentiful again and the cycle would

58
00:01:53,940 --> 00:01:59,340
restart. Interspecies relationships like

59
00:01:57,270 --> 00:02:01,110
this are everywhere in nature and they

60
00:01:59,340 --> 00:02:04,500
tend to keep populations relatively

61
00:02:01,110 --> 00:02:05,970
stable over time. When environmental

62
00:02:04,500 --> 00:02:08,340
changes can tilt the scales in the favor

63
00:02:05,970 --> 00:02:11,609
of one organism and cause the entire

64
00:02:08,340 --> 00:02:13,590
loop to collapse. Western gulls are

65
00:02:11,610 --> 00:02:14,730
generalist species which means that they

66
00:02:13,590 --> 00:02:16,680
take advantage of many different

67
00:02:14,730 --> 00:02:19,500
resources and readily adapt to the

68
00:02:16,680 --> 00:02:21,239
changes in the environment. And as modern

69
00:02:19,500 --> 00:02:23,040
cities developed they began to generate

70
00:02:21,239 --> 00:02:25,739
an abundance of organic waste for the

71
00:02:23,040 --> 00:02:27,359
birds to eat. Once gulls were able to

72
00:02:25,739 --> 00:02:29,459
lean on the resources that dumps and

73
00:02:27,360 --> 00:02:31,290
fisheries provided them the population

74
00:02:29,459 --> 00:02:34,440
was no longer limited by the population

75
00:02:31,290 --> 00:02:35,670
of steelhead trout. Today Western gulls

76
00:02:34,440 --> 00:02:38,010
eat three times the anthropogenic

77
00:02:35,670 --> 00:02:40,200
resources as historic gulls and their

78
00:02:38,010 --> 00:02:42,720
population has grown two to four times

79
00:02:40,200 --> 00:02:44,820
what it was before. While the average gull

80
00:02:42,720 --> 00:02:46,290
is eating less fish than before their

81
00:02:44,820 --> 00:02:48,510
numbers have completely overwhelmed the

82
00:02:46,290 --> 00:02:50,880
steelhead trout population pushing them

83
00:02:48,510 --> 00:02:52,160
to the edge of extinction. And steelhead

84
00:02:50,880 --> 00:02:54,269
are not alone

85
00:02:52,160 --> 00:02:55,620
Many species around the world are

86
00:02:54,269 --> 00:02:58,220
threatened by human-provided subsidies

87
00:02:55,620 --> 00:03:00,030
to their predators or competitors

88
00:02:58,220 --> 00:03:01,620
Millions of birds and other

89
00:03:00,030 --> 00:03:02,820
opportunistic creatures have become

90
00:03:01,620 --> 00:03:04,799
dependent on landfills

91
00:03:02,820 --> 00:03:08,410
and discarded bycatch, reshaping

92
00:03:04,799 --> 00:03:10,420
ecosystems to center around human waste.

93
00:03:08,410 --> 00:03:12,100
Other coastal cities that experience

94
00:03:10,420 --> 00:03:13,929
this issue have attempted to address it

95
00:03:12,100 --> 00:03:15,519
by closing dumps and temporarily banning

96
00:03:13,930 --> 00:03:18,130
trawling techniques for fishing that

97
00:03:15,520 --> 00:03:20,860
discards 7 million tons of bycatch every

98
00:03:18,130 --> 00:03:22,780
year. The most potent legislation right

99
00:03:20,860 --> 00:03:24,550
now is the European Union's ban on

100
00:03:22,780 --> 00:03:26,620
fishery discards which will require

101
00:03:24,550 --> 00:03:28,000
fisheries to bring all bycatch ashore

102
00:03:26,620 --> 00:03:29,770
instead of dumping it back into the

103
00:03:28,000 --> 00:03:32,890
ocean for opportunistic animals to

104
00:03:29,770 --> 00:03:33,940
scavenge. And while the EU intends to

105
00:03:32,890 --> 00:03:36,549
protect threatened and endangered

106
00:03:33,940 --> 00:03:38,410
species there are legitimate concerns

107
00:03:36,550 --> 00:03:40,030
that this law may actually compound the

108
00:03:38,410 --> 00:03:41,740
damage that commercial fishing already

109
00:03:40,030 --> 00:03:43,420
inflicts on sea life by completely

110
00:03:41,740 --> 00:03:45,160
removing the energy stored in bycatch

111
00:03:43,420 --> 00:03:46,530
and decreasing the resilience of the

112
00:03:45,160 --> 00:03:48,549
ecosystem

113
00:03:46,530 --> 00:03:50,260
Unfortunately no one knows how to

114
00:03:48,550 --> 00:03:52,150
reverse the effects of decades of human

115
00:03:50,260 --> 00:03:54,540
exploitation and generations of seabirds

116
00:03:52,150 --> 00:04:07,180
that rely on wasted food for survival

117
00:03:54,540 --> 00:04:07,180
[Music]

118
00:04:11,500 --> 00:04:18,569
[Music]

119
00:04:18,738 --> 00:04:20,798