1 • The National Hydrography Dataset’s Watershed Boundaries, that we use extensively, includes barrier islands, and so, fishes in bays and estuaries, as well as the outer coast are included. Thus many of the 649 species known from “Texas” are only in the bays and inshore Gulf of Mexico. • The reason for “about 282” is that it’s hard to draw the line freshwater/marine line, and new species are still being discovered and described. • All species shown here are known from “freshwater” of Texas • Thus the Colorado has a bit more than 1/3 of the state’s total freshwater fish diversity

2 • Our Fishes of Texas database is described at the top • It is based entirely (so far, but that will soon change) on less colorful preserved specimens like those on our own collection’s shelves (shown in part on left), but color is not as important as is the simple fact that the specimens were preserved and deposited in the world’s Natural History Collections where they last for a very long time. • Note little difference between specimens collected 130 and 10 years ago. • Museums have always been very careful to preserve not only specimens, but also the original data about their collection. • The specimens and data together thus can tell us a lot about the history of fish communities in our state than we’d otherwise not know. • And, because we can inspect specimens any time, we can be sure we know exactly what species we are talking about, and not be plagued by uncertainty of written identifications. • Mis-identifications of fish species are common, even in museums, but if we have specimens, past errors can usually be corrected. • Our database extends back to Collections made in the 1850s to present. • Not unexpectedly, old specimens are relatively scarce, but starting 70 or so years ago, Texas was being pretty thoroughly sampled by biologists who were preserving their specimens in natural history collections.

3 We’ve invested a lot of work in this database 1. systematically compiling the data from all museums we can find that have TX specimens, we 1. reformat and import it into the database, and since nobody had GPS’s back then, 2. manually figure out, one by one, the latitude/longitude of all of the places where they were collected, 3. find “outliers”, and check those specimens to be sure they’re not mis- identified, and 4. finally, we use computer modeling of distributions to help fill in blanks between collections. 2. Then we spend a lot of time programming the web interface to provide the information to the world.

It’s a massive, and never-ending task, but we’ve made good progress.

4 Our website can easily extract a list of all species known from different geographies: the whole state, any county, or any major river basin or sub-basins within them.

The Colorado has 105 freshwater fishes.

And, our checklists include info about how certain we are about this list, marking “suspect” records, and telling the user how many records we have of each species in the selected area.

We also flag non-native species.

Unfortunately, 25% of the Colorado’s fish fauna is not native.

5 The data are then easily mapped.

Dot size increases with number of collections at a place (zoom in to see each).

Gray marks native range.

Green = specimens we’ve examined ourselves.

Blue = those for which we see no reason not to trust original identifications.

Yellow and red dots are those we’ve flagged as likely to be incorrectly located or mis- identified, but we have yet to examine the specimens.

The Blacktail Shiner is one of the state’s most common and widely distributed minnows, native to all of Texas’ major river basins except the Río Grande, where it was introduced. There are relatively few other species so well collected.

The other species here is another minnow, but one that has yet to be described by scientists. It has a small range in the Colorado River’s San Saba sub-basin.

6 This endangered species is found in only one spring in Menard County, but for many years (1950s – 80s) it was well studied.

In the 1960’s it was found to be threatened by hybridization with the common Mosquitofish. A rock dam isolated the springhead from downstream reaches, but it was breaking down allowing Mosquitofish to enter the springhead.

That problem was rectified by the Hubbs lab repairing the dam in 1970s and follow-up studies demonstrated that hybridization decreased.

About 10 years ago the dam was noted to be failing again.

8 years ago, when last inspected by qualified ichthyologists, pure individuals still were found in the spring head.

FWS offered to assist the landowner with repairs to the dam, but apparently negotiations were never finalized and I’m told there have been no official follow-up visits to assess the species’ status.

7 Despite the name “Guadalupe Bass”, most of the range of this popular sport fish is in the Colorado basin.

8 There’s a long, ongoing, and successful history of recovery efforts for this once endangered but also sport fishing species by TPWD, and I’d refer anyone interested to the brand new Conservation Plan they just released.

9 Naked Goby, native to the Texas coast, was discovered in the Upper Colorado about 10 years ago, and has been apparently expanding and showing up in other basins since then.

At least in the Colorado, it appears restricted to extremely altered (high sediment loads over gravel) that few other fishes utilize. We don’t know what its impact will be. However, it is in the same general area as Greenthroat Darter, a Texas endemic of conservation concern, with which it might interact if it continues expanding.

10 The Río Grande Cichlid (or Perch), native to that basin has been expanding for many years. It clearly interacts with native sunfishes and many other species, likely to the detriment of the natives.

Sharpnose Shiner was listed as endangered by USFWS a few years ago. Critical habitat was designated in the Brazos. Close relatives of this species have been extensively studied elsewhere (does the endangered Rio Grande Silvery Minnow ring any bells?). Their eggs drift downstream and if they end up in a reservoir before hatching, they die. Dams and the related habitat fragmentation were likely a primary contributor to endangerment of this species for the same reason.

The listing mentions specimens from the Colorado in the early 1940s, but dismissed them as introduced. When we were checking specimen ids at the Smithsonian we examined some specimens of a relative of this species collected in Austin in 1882 and determined them to be mis-identified – they looked a lot like Sharpnose Shiner, but we couldn’t be absolutely sure. FWS funded us to look deeper, and after checking thousands of specimens in many jars of relatives of Sharpnose, we ended up with more records of this species or a close relative from the Colorado that ranged from 1882 into the early 1970s. We still can’t say for sure that these are Notropis oxyrhynchus, but if not, they are a close relative that was never described scientifically. Unfortunately, whatever it was, it looks to be now almost certainly extinct.

11 Our large, now well normalized, database now allows us to start getting into rigorous statistical analyses of temporal trends.

The left-most graphs depict temporal trends in what can be described as detectability or “relative abundance or common-ness” (on the Y or vertical axis) controlled for a constant amount of sampling in each of the variable time intervals (earliest to most recent left to right) on the horizontal axis. Higher values indicate more frequent detection of the species. So, for Sharpnose, as sampling effort is held relatively constant, observation of the species has become more rare over time. Obviously, very different things are going on with these two species, but at least these two trends are exactly what we expected. While Sharpnose Shiner has been becoming increasingly rare over time in the two basins where it occurs or occurred, the Cichlid is becoming relatively more frequently collected as it has steadily expands into its new non-native range. We’re in the process of refining these analyses and improving statistical power. The results look very promising at this preliminary stage. We hope that by doing such analyses for all species, we might discover worrisome, but still undetected trends in other species early, and thus be better able to address them via appropriate management.

12 Our large geospatial database also allows us produce Species Distribution Models. We started doing this when the methodology was quite new, but it’s now very well established in Ecology.

I won’t get into the details, but will show you how to read these – the model basically fills in the gaps between specimens by using basic environmental data and the specimen records to computing a probability of finding a species in every kilometer of stream. These are simply heat maps – red hottest (> 90% of finding it) and yellow is essentially a coin toss (50%), with white being < 50%.

When we first produced these models, we were skeptical about their value in practice, so came up with a basic way to empirically test them.

13 We looked for a relatively large watershed that had never been sampled. The James River, a Llano River tributary just below Mason, fit the bill. It’s also sparsely populated and so relatively un-impacted by humans. We used all of our models for the Colorado River basin species to predict the fish community that we would expect to find in the James River basin. They’re all arranged from most to least probable in the graph, and we colored those we actually collected with UT’s Longhorn Orange, and those we didn’t are colored blue. Almost every species the models said had > 50% probability of being found was found in our samples, and we turned up only a couple of species with < 50% modeled probability. A closer look at the statistical descriptors produced by the modeling program revealed that the models for the small number of species that we “got wrong” (orange ones in the mostly blue range and blue ones scattered with a bunch of orange ones) were not really very good models to begin with. The models’ statistics themselves could have told us in advance that we shouldn’t have believed them in the first place!

In Barton Creek we sampled intensively over a few years shortly before the models were produced, so already had the list of everything we found. Adding our historical data to what we thought should be there revealed 7 more species that definitely were there before we sampled, and our models told us there probably used to be 7 more that were never sampled.

14 We then used our models in conservation planning programs to help find areas that would provide “best bang for the buck” for conservation – what areas have the best habitat for the greatest number of species of conservation interest?

TPWD has now used the results to formally establish the Native Fish Conservation Areas pictured here, and organized local stakeholder groups in each to help coordinate efforts and collaboratively prioritize projects with the limited funding available to them.

15 16 There are 3 commercially important, closely related eel species that share the same basic life history and are morphologically nearly indistinguishable.

They are all called Unagi in the world’s sushi market. I’m guessing most of you have sampled it.

Virtually all unagi consumed on this planet now comes from aquaculture in Asia (check out the annual production in the producing areas - 260,000 metric tonnes of eels per year!

1. Unfortunately, nobody has figured out how to get eels to reproduce in captivity, so every eel in culture (and thus in sushi) originates as a wild-caught glass eel.

2. The Japanese started this aquaculture in the late 1800s with their own eel species, caught locally.

3. Asian countries (primarily China) started aquaculture in the 1990s with the same species. The Japanese Eel was quickly heavily overfished and collapsed.

4. Everyone then went to Europe to catch glass eels of that species for the ponds in Asia. That fishery quickly started to decline and the EU closed it in 2010.

17 5. So, everyone started buying American glass eels caught along the Atlantic coast of the US and Canada.

6. It didn’t take long before US States and Canada detected sharp drops in the numbers of glass eels/elvers entering their rivers. The price paid to fishermen for glass eels hit $2,600/pound in New England in 2014 as most states and Canada closed their fisheries. Eel fishermen started carrying guns and some dealers lost hundreds of thousands of dollars overnight to theft of tank-held glass eels while they were out collecting more.

17 1. If eels in TX are anything like those elsewhere (they are the same species at least) it seems likely that some enterprising Texans have figured out how to harvest the glass eels that obviously must be entering TX rivers, but if so, nobody’s talking,

2. Biologists in TX know very little about the species in this state – note the dearth of data in the maps provided by these major biodiversity data providers

3. A few years ago, it started looking likely that National Marine Fishery Service would list the American Eel as Endangered, stopping all fisheries.

4. That got the attention of the Texas Comptroller, more for potential impact on water management (dams block eels, eels need certain flows, etc.) than potential for starting a glass eel fishery.

5. We had always wanted to study these cool critters, so when the Comptroller released a request for proposals, we took the bait, hook, line and sinker…..

18 The Comptroller had determined that economic impacts related to proposed USFWS listing of the eel as endangered would be restricted mostly to lower parts of rivers (blue counties), below the lowest major dams.

Data that we compiled (largely from FoTX database, but also non-specimen-based observations) for the proposal showed many recent occurrences far upstream of dams in many Texas rivers

19 Only specimen-based records are mapped here - native range of American eel in Texas clearly included all of the state’s major rivers from their mouths to near headwaters of most.

Paradoxically, none of the TX specimens are of glass eels.

20 Let’s look at the eels’ journey to TX in more detail.

• It’s pretty easy to see the major currents that pull them out of the Sargasso and scatter them via the Gulf Stream all along the Atlantic coast of this country. Their European cousins (who also spawn in the Sargasso at a different time of year) stay in those currents all the way to Europe.

• There are only a couple of records of leptocephali in the Gulf of Mexico, and just a smattering of them in the Caribbean.

• But leptocephali were long ago tracked entering the Caribbean from the Sargasso.

• You can see the maze of crazy, ever-changing massive swirling eddies from there into the Gulf of Mexico. It would surely take them a very long time to get to Texas via the Caribbean, and my guess is they might show up in TX only in those years that have just the right currents. They change quite a lot from year to year.

• It’s interesting that Panama and Costa Rica both have reasonable number of eels in their rivers, but there are very few records from elsewhere in Central America and México, and the only Mexican specimens are from the far NE, near Texas.

21 As alluded to before, glass eels are well studied along the Atlantic coast.

They show up predictably every year in spring, group up, and over a 4-6 week period, when moon and tides are just right, they all head up rivers at night, stopping to hide and rest during the day.

These tiny 3-4” guys go for it, covering 3-13 miles/night!

If they were doing this on Mopac (or in Shoal Creek right alongside it as they surely used to), leaving Ceasar Chavez at nightfall, they’d get to somewhere between Spicewood Springs Road and the Domain by morning!!!!!

They are known to be adept at surmounting obstacles, but the places eels turn up the Austin area make you wonder how they do it.

22 Night swimmers see good size yellow eels in Barton Springs regularly, and anglers in Ladybird lake occasionally reel them in.

23 But before they could get there, the big dam downstream would, at first glance, seem to be a definite immigration impediment…

But they did, and still do – the yellow eels here were once glass eels.

24 25 Here’s some cool documentation on what glass eels and elvers do to ascend Connecticut rivers….

26 27 28 29 30 31 32 Some of Longhorn dam’s lift gates (used only in emergencies) leak, and since the lake (on the right) is kept at a more or less constant level, the water that passes through them is at a pretty much constant head of about 15 feet so the discharge through the leak and across the relatively short (few meters) and gently-sloped concrete ramp below is probably more or less constant. This ramp is thus very similar to special-built ramp traps used along the U.S. Atlantic coast to capture and count incoming cohorts of glass eels and elvers for their standardize eel monitoring programs.

I’d love to put a video surveillance system on this to detect elvers like those of the preceding slides looking to continue their upstream journey. It seems likely that at least some might wiggle their way through into Ladybird Lake.

Maybe watching eels trying to get into Ladybird Lake could become as popular as bat watching!

33 When they caught a couple of small eels on one of their ichthyology class field trips, our colleagues at A&M texted us. We raced out and went into overtime throwing every trick in the book at them, to beat the Aggies 17 eels to their 2. We did this in the area right below Coleto Creek dam using methods most ichthyologists and fisheries biologists don’t commonly use.

34 More recently, social media has been a big help. TPWD asked the state’s anglers, via Facebook, to report their eel catches. The results, many with photos, are a nice complement to what the museum record was telling us, and in most cases, documenting more recent occurrences, many far upstream.

If you’ve ever seen an eel anywhere in TX, please let us know (see the last slide).

35 But, eels never cease surprising us. We never would have looked here. The folks who manage this place had seen our flier (below) and gave us a call.

36 PLEASE LET US KNOW IF YOU EVER SEE AN EEL ANYWHERE IN TEXAS (OR ANY OTHER ADJOINING STATE FOR THAT MATTER), and check our out website (https://sites.cns.utexas.edu/hendricksonlab) where we’ll keep adding more information about eels and our other cool fish projects

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