cc  >> Research scientist at --  (no audio)  He's a curator of fishes at the  University of Wisconsin-Madison  Zoological Museum.  He received a bachelor's degree  from Union College  in Schenectady, New York,  in biology, and both a master's  and a PhD from the University  of Wisconsin-Madison in zoology.  And John's specialty is  the ecology and management  of Wisconsin fish.  So now it's time to turn it over  to John.  >> Thank you Michael.  Matt gave you a very nice  overview of what climate change  is likely to do with two fish in  Wisconsin.  In fact, Wisconsin has 164 fish  so I'm responsible for the other  162.  So I'm going to talk about the  other fish.  The non-cold water fish.  Which actually comprise the  majority of the fish in the  state. 

 As I said, Wisconsin has 164  different fish species.  About 24 of them, or 15% or so,  can be classified as cold water  species.  And that includes the brook  trout, shown here, and the brown  trout that Matt focused on in  his presentation.  As Matt said, cold water fish  have an optimal temperature for  growth and metabolism and so  forth, that's on the cold end of  the spectrum, roughly 14 to  20-degrees C depending on the  species, 57 to 68 Fahrenheit.  And anything much above 24 C, or  75-degrees Fahrenheit, is lethal  if exposed for any length of  time.  So we've heard all about them.  So what are the other fish?  Well, there's an intermediate  group that we term cool water  fishes.  Roughly 31 species or a little  more again about 15%.  And that includes some very well  known and popular sport fishes  like walleye, yellow perch,  muskies, northern pike, as well  as a number of non-game species.  These fish, as the name implies,  prefer cool rather than cold  water. 

 They're optimal temperature, as  you can see, is a bit higher.  And in fact, some of their  optimal temperatures approach  the lethal temperature for cold  water fish.  And their lethal temperature is  much higher, about 88-degrees  Fahrenheit.  So pretty warm water.  And then finally there's the  vast majority of the species in  the state, probably two-thirds  of the species in the state,  would be considered warm water  fishes.  These are fish, things like  catfish, bluegills, large mouth  and small mouth bass.  A whole host of non-game fishes.  Carp, as Matt pointed out.  Many, most in fact, of our  threatened and endangered  species are considered warm  water fishes.  So there's just a tremendous  diversity, tremendous variety in  that group. 

 Their optimal temperatures,  again as Matt had talked about,  are actually higher than the  lethal temperature for trout.  And their lethal temperatures  approach bath water sorts of  temperatures.  So it's unlikely in a state like  Wisconsin with a temperate  climate that even under climate  warming that it's ever going to  get so warm that temperatures  are going to be lethal for warm  water species.  So that's the breakdown of the  species in the state, now let's  look a little bit at the  breakdown of temperature in the  state.  As Matt talked about, we  developed a model that allows us  to predict temperature in all  the streams in the state.  So this is just talking about  streams.  And it allows us to estimate  what the maximum temperature is  going to be in each of those  streams during the summer.  And we've actually broken the  streams into little tiny  segments.  Each segment is about a  kilometer, half a kilometer in  length.  So there's about 120,000  different segments of stream in  this state. 

 And what this is, if this shows  up, is each of these bars, this  is a frequency diagram, so each  of these bars indicates the  number of stream segments that  have a certain temperature.  So this blue bar, what happened  to my cursor?  There it is.  This blue bar indicates that  about 20,000 of these little  stream segments have a water  temperature, a maximum summer  water temperature between 19 to  20-degrees C.  That's 66 to 68 Fahrenheit.  And about 23,000 have a  temperature from 20 to 21 and so  forth.  And I've color coded these based  on which ones are optimal for  cold water fish, which ones are  optimal for cool water, which is  in green, and which ones are  optimal for warm water, in  brown.  And you can see that the vast  majority of our streams are  actually optimal for cool water  fishes.  They're kind of that  intermediate temperature.  But there are lot of stream  segments that are optimal  for cold water fishes;  there are lots that are optimal  for warm water fishes.  So we have this diversity of  thermal properties out there and  that's one of the reason we have  this wide diversity of fish  occurring in this state. 

 That's things look like now.  Now as Matt indicated, and it's  fairly obvious, with climate  change things are going to get  warmer and water temperatures  are going to increase.  And Matt gave you a lot of good  information about how it's going  to vary depending on where you  are and depending on conditions  of the stream and so forth.  But just for a very simplistic  sort of exercise, what would  happen if all the streams in the  state were to increase by  2-degrees?  And again that's not realistic  but just as sort of a thought  exercise.  Well, this is that same sort of  distribution shifted 2-degrees  to the right.  And now you can see a very  different distribution for  available habitat for different  types of fish.  You can see that, in fact, now  there's very little water that's  optimal for cold water fishes.  There's still lots of water  that's optimal for cool water  fishes.  And now all the sudden the  dominant category out there is  warm water.  Now that's just a two degree  shift in maximum water  temperature in summer. 

 And 2-degrees is not by any  means an extreme scenario based  on a lot of the climate models  for the next 50 or 75 years or  so.  So that begs the question then,  will catfish take over  Wisconsin?  Well, we can use some of those  models that Matt talked about to  actually look at that.  Now he's described these various  models that we've developed to  look at the distribution of  suitable habitat for different  species in the state.  And he compared brook trout and  brown trout.  I'm going to compare brook trout  and channel catfish, a warm  water species.  So you've seen all the stuff on  the left side of this graph  already but the stuff on the  right side, the catfish stuff,  is new.  So this is what the model says  things are like currently.  And you can see that actually  right now there's more suitable  habitat for brook trout in the  state in terms of stream miles,  stream kilometers, than there is  for catfish.  So there's almost  18,000-kilometers of potential  brook trout habitat and only  less than 5,000 of potential  catfish habitat.  And we'll do that same exercise  that Matt went through. 

 We'll increase temperature by a  degree, water temperature and  air temperature and now all the  sudden the brook trout drop down  to about 5,000 and, not  surprisingly, the catfish jump  up by about 1000, 1300 or so,  27%.  So you can see in particular  that where you're seeing, if  this works, you're seeing big  losses of brook trout down in  this part of the state.  And then you're seeing some  gains in catfish they're kind of  creeping into the northern tier  of the state.  If you go to 3-degrees.  You see, again, more losses for  the brook trout, more gains for  the catfish but the gains aren't  particularly dramatic.  And if you go to 5-degrees C   there's essentially no gain for  the catfish and a complete loss  for the brook trout.  So, in fact, catfish are not  taking over the state when it  gets warmer.  And if you look at that  graphically you can see that  basically as the trout  populations are declining, the  catfish populations are  increasing but the rate of  decline for trout is much  greater than the rate of  increase for catfish.  So it's not a one-to-one trade.  It's not like for every  kilometer of trout stream we  lose we're going to gain a  kilometer of catfish habitat. 

 It's not even close to that.  And that's generally true  because there are other things  besides temperature that limit  where catfish occur.  Obviously, if things are too hot  for you to survive, that's going  to eliminate you.  But just because things are  ideal for you temperature-wise  that doesn't mean other factors  in the environment are going to  be ideal for you, and that  doesn't mean necessarily you're  going to exist at every site  that is thermally suitable.  There's going to be other things  that won't be suitable.  And catfish, in particular, are  river species.  They need big volumes of water.  They're not going to able to  survive in a lot of the little  tiny streams where trout species  are able to thrive.  And in fact that's a general  trend for almost all of the cool  water and warm water game fish  in the state.  Trout are adapted to live very  well in very small creeks and  small streams. 

 Our cool water and warm water  species are not.  They are adapted to live in  larger rivers and in lakes.  So the fact that all these  little tiny streams become  warmer doesn't really create  that much new habitat for a lot  of our cool and warm water  species.  So bottom line is that there's  going to be a change in our  fisheries.  There's going to be some  increase in our warm and cool  water fisheries but it's by no  means going to offset the  decline in our trout fisheries.  So there's going to be a net  loss of fishery potential in  terms of sport fish and things  people fish for.  Now of those 164 species most of  those species are actually not  sport fish species.  They're not thing that is  anybody actually fishes for.  And so what's going to happen to  some of these non-game species.  And, in particular, some of  these species that are adapted  to live in small streams. 

 So they're not necessarily  precluded from occupying a small  stream that a trout would also  be found in.  And again, there's 100 different  species.  I just picked two of them that  provide a nice contrast.  On the left is the rosyface  shiner, it's a small native  minnow.  It's a habitat specialist.  It has very particular habitat  requirements.  It's also very intolerant of  pollution and environmental  degradation, things like that.  And at the other end of the  spectrum we have green sunfish.  It's a small sunfish, too small  to really support any kind of a  sport fishery.  It's a habitat generalist, it  can live kind of anywhere and  it's highly tolerant of  pollution. 

 But both of these are warm water  species, they need warm water in  order to survive.  So now we'll do the same sort of  exercise we did with the brook  trout and the catfish but now we  look on the left, we'll have the  rosyface shiner; on the right,  we'll have the green sunfish.  And I won't go through the whole  thing.  I'll just show you a couple  slides here.  But basically at current times  there's about 9,000-kilometers  of rosyface habitat and about  13,000-kilometers of green  sunfish habitat.  And green sunfish are primarily  in the southern half, southern  two-thirds of the state, where  rosyface are scattered kind of  all over.  Well, basically just go to one  extreme, what happens if  everything goes up 5-degrees?  Well, there's certainly  increases in both species.  Both of them increase  substantially but look at the  differences in increase.  The tolerant generalist species  has more than quadrupled in  distribution and abundance,  where the sensitive specialist  species has only increased less  than 50%.  So there's going to major  differences in how non-game fish  respond as well as sport fish  respond. 

 And basically the message here  is that what's going to happen  is as the trout disappear  they're going to be replaced by  a lot of tolerant, generalist  kind of species that are already  common, that are already all  over the place.  And you're not going to see big  gains in the a lot of the rare  things, a lot of the more  sensitive things, the threatened  and endangered species for  example.  They'll increase a little but  not to the point that all the  sudden they're going to become  common.  And so there is going to be a  response.  And so basically what you're  going to see is what happens to  trout streams as they get warm.  Is this group of small, of cold  water intolerant and habitat  specialist species such as the  brook trout, and then there's  the non-game cold water species  -- on the bottom.  They're going to be replaced by  a different set of very tolerant  habitat generalist non-game  species.  There's not going to be replaced  by muskies or walleyes or things  like that.  They're going to be replaced by  green sunfish and creek chubs.  And so there's going to be a net  loss of diversity in the state  and a net loss of fishing  opportunities even though there  will be some gains in particular  places for certain species. 

 So far we've been talking about  places where things are going to  expand or change, where habitat  conditions are going to get  warmer and so you'd expect the  cold water species to disappear  and maybe the warm water species  to expand.  What's going to happen in places  that are already cool or warm  water habitats now?  And that includes almost all of  our lakes in the state.  There are a handful of cold  water lakes in the state but the  vast majority have either cool  and/or warm water habitat in  their shallow areas at least.  So these are places that already  have cool or warm water fishes.  And so what's going to happen  there?  Well, if the water gets warmer  in these lakes, there's some  upsides.  There's going to be longer  growing seasons and milder  winters and that's going to  manifest itself, by and large  faster growth rates in most  species including most sport  fish species, all other things  being equal.  And perhaps better survival.  The winter in Wisconsin, as  we're aware just having gotten  through one, is kind of a harsh  one for not only us but for fish  as well.  And particularly young fish  there's often a lot of  mortality, a lot of death for  young fish, particularly during  harsh winters.  So milder winters may mean that  there's better survival of a lot  of the young small fish in the  system. 

 So there's some upsides.  You may have bigger fish, you  may have faster growing fish,  there may be more fish in some  of these habitats.  So what is the downside of  warmer water?  Longer growing season, mild  winters.  It's a two-edged sword.  There's some pluses but also  some minuses of increased  temperatures.  First there's likely to be  poorer water quality.  Again, all other things being  equal.  Warmer temperatures are going to  be more beneficial for nuisance  algae, for bacteria, all those  kind of nasty things that make  water unswimable and smelly,  and stuff like that.  It's likely to make the state  more vulnerable to invasion by a  whole bunch of different  nuisance exotic species.  Perhaps make it more vulnerable  to invasion by different kinds  of diseases and things like  that. 

 So there's going to be some  downsides as well.  The fish may be growing faster,  they may be surviving better but  they may have more competitive  exotic species, and poor water  quality to deal with, things  like that.  And so depending on where you  are there could be some pluses,  there could be a benefit, the  fish populations, the fisheries  could get better or worse.  It really depends on the  situation.  Now, we talked just about water  temperature so far, let's turn  to precipitation and Matt told  you a lot about how important  that is, and in particular  there's going to be a lot more  extreme precipitation events.  Those huge rain storms that dump  inches of rain in a short time  period and cause all sorts of  flooding.  Along with that even if the  climate gets generally wetter,  when you have more extremes that  also means you're going to have  more dry periods because if all  the rain falls at once that  means there's going to be long  stretches when no rain falls.  So even if it gets wetter here  we're likely to have more  droughts.  And an obvious impact of  droughts, particularly in  smaller streams and smaller  lakes, is they're just going to  dry up and, obviously, that's  bad for any type of fish, cold  or warm, there's going to be no  habitat there.  There's also quite a number of  fish that actually benefit from  high water, from flooding during  certain times of the year,  particularly in the spring. 

 A classic example of that is  northern pike that actually  spawns in flooded vegetation,  swamps and marshes, and  typically, the wetter spring it  is, the more things are flooded  in the spring, the better  northern pike do.  And so if you have very dry  springs and marshes aren't being  flooded, they're no longer  accessible because everything  has dried up there will be poor  pike spawning.  Now the converse, when we talk  about floods, they can be  beneficial at some points in  time but they can also be very  harmful at other points in time.  This is a picture of a stream up  in Sauk County during one of  those really bad floods last  summer, and this stream is  usually about 3 feet wide and  you can see here it's about 100  yards wide at this point.  When you have a lot of floods,  as Matt alluded to, you get a  lot more erosion, you get a lot  more runoff, you get a lot more  sediment in the streams, you get  a lot more nutrients in the  stream.  That causes problems with water  quality.  It fills in the stream channel  with mud and silt and things  like that.  So there can be a lot of habitat  losses and a lot of habitat  damage from floods, particularly  these extreme floods if they're  more frequent and more severe.  Another issue is that, while  there are some species like  northern pike that benefit from  high water from flooding, there  are other species like small  mouth bass that are really  harmed by flooding during their  spawning period.  Small mouth bass spawn late in  the spring and the large male,  shown up in the top, will guard  a nest that he makes, on the  bottom shown on the right, and  guard the eggs and larvae until  they're large enough to fend for  themselves, shown down here on  the left. 

 They really require nice, calm,  gentle flows because the eggs  and larvae are very susceptible  to be washed out, to be damaged  by high flows and by high  flooding.  And it turns out it doesn't take  a whole lot of flooding to  actually completely wipe out the  reproduction for a particular  year in a particular stream.  So here's some data we've  collected over many years  looking at the maximum rise in  stream stage, that is how much  the stream actually goes up from  its normal base flow during the  spawning period which, as I  said, is in late spring, early  summer.  And how that correlates then  with how many young of the year  juvenile small mouth bass are  produced in the fall.  And you can see basically all  the water has to do is come up 6  to 12 inches in these streams  and that basically eliminates  the reproduction of that year.  That's a one year event, bass  live several years so just  happening once doesn't  necessarily eliminate the  population and the fish are  adapted to deal with that.  But if it's happening more and  more frequently and the storms  are more and more severe then  eventually you could have these  populations disappear.  Even though the water  temperature and a lot of the  other conditions are actually  better in these streams.  But the extreme events could  eliminate the fish.  So let's sum up what the effects  are on warm water and cool water  fishes. 

 If we're dealing just with the  warmer water aspect of things  there is going to be expanded  distributions, there is going to  be some gains in habitat for  catfish and for bass and even  for walleye and muskie and  things like that.  But those gains are going to be  relatively modest and they're  going to be nowhere near the  losses that are likely to occur  under some scenarios in trout  populations.  So there's going to be a net  loss in fishing opportunities  around the state.  Doesn't mean fishing is going to  go away but it's not going to be  as diverse and interesting as it  is now.  And basically the big winners  here are these sort of  jack-of-all-trade tolerant  generalist species that are  already pretty common.  And these, you know, less common  non-game and threatened and  endangered species maybe  increase a little but really  aren't going to benefit a whole  lot.  There's probably going to be  faster growth and better  survival, at least  in certain places.  So you may catch bigger fish in  some places.  But that may be offset and may  even be a negative in some  places because of poor water  quality issues, more exotics,  disease, all those sorts of  things.  If you're talking about  precipitation, particularly  stream precipitation, if you  have more droughts, you're going  to have more habitat loss. 

 If there's more floods, you're  going to have all this increase  erosion runoff, and again that's  a type of habitat loss, and  ultimately less successful  reproduction.  So adaptation, first of all I'll  echo what Matt said.  We have to plan for these  extreme events.  We can't be surprised when they  occur.  We have to assume they're going  to occur.  And they're going to occur more  frequently and our management  and everything has to build that  in to our planning.  Because the tendency of warmer  water and more extreme events is  likely to reduce water quality,  reduce habitat quality, now is  the time to be strengthening and  making our environmental  protection efforts more  stringent rather than less  because, all other things being  equal, environmental quality is  going to go down unless we do  something about it.  And as Matt indicated, that's  particularly relevant in terms  of land management.  In terms of how we manage  vegetation and land use along  streams, along lakes and in the  watersheds in general.  And I'll just end finally by  pointing out that what we're  doing here is looking in a  crystal ball and trying to  predict the future which is  always risky. 

 So these are our best guesses at  this point but chances are some  of them are wrong so we should  always expect the unexpected.  And that's how I'll end.  (applause)