Monday, March 24, 2014

Beaver/Salmonid Workshop Part II: Santa Ynez Beaver Tour

Duane Nash
Well all-righty then the conference is over and I have had a couple of days to digest all the things I saw and learned. The venue was awesome, Santa Barbara breathtaking, and the salmonid restoration federation (SRF) did an outstanding job with organization, breadth of presenters, and even the food/coffee/snacks offered up, including a lunch, exceeded expectations. I do intend to get to the talks I saw on Friday and Saturday but today I want to finish up on the beaver/salmonid workshop and field tour because, you know, beaver... and salmon.

Historic and Current Distribution of Beaver In CA. CDFW Lanman et al

But first a couple of thing with regards to the blog. Coincident with the recent publication by CA fish and wildlife paper Lanman et al documenting the historic occurrence of beaver though out the majority of California and the conference on beaver/salmonids my little blog has seen a slight uptick of visits. Granted beaver in semi-arid socal is a bit of a niche blog market anyways- the average socal brah is probably ignorant on beaver in socal, or southern steelhead for that matter- it is still encouraging to see daily page visits go up from a trickle of 3 or 4 visits to getting up in the double digits on the reg. Additionally I discovered a facebook open group Beaver Management Forum where I put my posts and that has helped with attention too- make sure to join!!! And you too can help southland beaver as well simply by liking my posts on facebook- even if you don't read them haha- or sharing on on your wall it all helps.

Martinez Beavers. c/o Ted Guzzi
Now back to the beaver workshop. It was great to meet and talk to so many beaver believers (sorry Justin we are taking the name back). People like Martinez Beavers own Heidi Perryman, "Rickipedia" Rick Lanman, and the Water Institute's Kate Lundquist and Brock Dolman. I also met and had nice conversations with Eli Asarian of Riverbend Sciences/beaver mapper, Shari Witmore of NOAA, Kevin Swift of swift water design- an emerging player in California non-lethal beaver management- as well as beaver advocate and water lover- great website/blog I will put it on my blogroll Kevin!! Several people also approached me and said that they do read my blog- cool!! I was a little disappointed that I did not come across any other significant beaver advocates from the southland- it was a decidedly northern Californian lot there- but you know I just got to hold it down until the rest of the southland catches up. There were loads of people I never got a chance to talk to that I would have liked to chatted up. Sometimes a lot of social contact shuts me down or I just get too shy. Never the less it was great to see such a significant beaver coalition present and as one salmon person said to me "beaver people are taking over this convention!" Well as one prominent salmon speaker said to me, paraphrasing: "us fish people can get a little myopic in our view, we do that well." So maybe beaver hooliganism is the shot in the arm that fish people need.

Duane Nash
In my last post I wrote about the first four talks at the workshop. Here I want to talk a little about the last two talks as well as the field tour.

Kate Lundquist. Martinez Beavers c/o Ted Guzzi
Kate Lundquist of the water institute gave a speech titled Policy Opportunities for Working with Beaver in Salmonid Recovery. The emphasis of the speech was actually on policy regarding beaver. A dry topic and one not as sexy as say how beaver dams serve as incubators for coho smolt or beavers role in dryland watersheds- but actually this talk was probably the most necessary in light of how beaver can and should be treated in the future in California. Basically there is not much to protect beaver in California. You can go read the CA fish and game code here. From Nov1-Mar 31 you can go out and hunt and bag just about as many beaver as you want. Additionally if you have a "nuisance beaver" you can apply for a depredation permit at any time of year- although in most rural areas it is probably safe to assume that first step is skipped. Now this may seem a bit depressing for an animal that we are trying to promote and distribute across the state but there is a silver lining in that the laws, or lack-there-of, concerning beaver in CA, offer some avenues towards change in a positive direction.... good job Kate!!!

Mike Callahan. Martinez Beavers c/o Ted Guzzi
Next up was Mike Callahan of beaver solutions, a well known innovator on non-lethal management of beaver. He showcased some nice designs with video of flow devices that allow fish to move through a box apparatus (lower flows) and then into the pipe itself and through the dam. Cool stuff and great to see this innovative design. Flew in from Massachusetts- what a rock star!!!

After lunch we headed off in caravan of jeeps and truck into the Santa Barbara back country for the Santa Ynez beaver tour. The Santa Ynez river is roughly cut in half by Cachuma dam which disrupts steelhead migration into the majority of tributaries and also inhibits the high velocity flows that would characterize this river system. And these two modifications are important to keep in mind. Tim Robinson, who has to balance the needs of fish, citizen water, and downstream water rights, often times is in, shall we say, a bit of a pickle. You see since the majority of good spawning tributaries are cut off by the dam the Cachuma board tries to maintain a nearby tributary and parts of the main channel with year round flows of, if I recall 2.5 cubic feet/second as a compromise to the loss of great steelhead habitat upriver from the dam. Which is a bit funny because, generally speaking, steelhead don't really use the main channel for spawning but as a "highway" to get to the cooler, smaller mountain streams with good gravels. So when beaver dams cause fines to build up, or water does not get to where it needs to go fast enough, or bass, bullfrogs, catfish, and carp proliferate, or flows can not be released to mimic natural flood conditions and blow out dams for water/fish movement guess who gets the blame? Yeah Tim is not as happy with beaver as many who see the benefits of beaver in less modified habits are but Tim has a definite mandate- and that mandate is for the benefit of steelhead and downstream water rights- not beavers. But all the negatives attributed to beavers in this watershed are, if looked at closely, a corollary of the inherent anthropogenic modifications to the system.

The above video is from a beaver dam south of the 154 bridge (so it does not get guaranteed year round flows) and directly upriver from the Encantado pool, a pool which becomes a veritable fish haven and sometimes killing grounds during the dry. Tim's speech and the questions are very pertinent and summarize a lot of the issues surrounding this intriguing watershed. As I mentioned to Rick Lanman later, Santa Barbara needs and can probably afford (hello SB county resident Ophrah) a desalinization plant. You may notice the dour look and vibe of many of the people. The water is low and warm. Not good trout habitat. If alluvial groundwater is not exchanging with beaver ponds due to lack of scouring flows or because of too much groundwater pumping- hyporheic exchange, where cooler subsurface flows intermingle with surface flows, one of the best attributes of beaver ponds - may not be occurring to the extent we should want. But I would not be so quick to assume this drought, and the low flows on the Santa Ynez spell doom for these beavers. Because they have lived here for 80 plus years since reintroduction. Because they live in much warmer/drier climes such as in the Mojave river and San Pedro river in Arizona. Because as I have had to correct several "trained" biologists (even at the conference) beaver do not eat fish, are amphibious but do not need to be immersed in water to live. Just look at these pics I stole from a site about the wildlife of the San Pedro river in Arizona. Read the account here.

Evidently a pair of beavers moved into a stretch of the middle San Pedro that usually flows underground, built a burrow, dug a canal for water, and then went about their business building a dam for flows that were not even there yet!!

Downstream from den
Bank burrow to the left with dug out canal. Pretty much just for drinking water?
Another view into the bank burrow
But they start making a home anyways...
And when the flows returned they had this!!!
San Pedro Beavers. like bandits in the night

Unfortunately, due to time constraints we did not visit the Alisail bridge stop in Solvang. But if you want to see what the beaver are doing there, during high flows from water release I assume check out my post Beaver Safari on the Santa Ynez River from September 2013. I did notice a lot of the dams have that u-shaped berm to them that was commented upon in the video. Also in that section I noticed a  lot of the dams only corralled a little side channel of the river- not the whole river.

So don't cry for the beavers of the Santa Ynez, they will get through this. However the steelhead, not so rosy looking for them...

Tim took us to a tributary of the Santa Ynez, Salsipuedes creek- which basically means "get out if you can!" referring to the heavy floods and scouring flows that pummel this creek and incise the banks. It is one of the best remaining steelhead creeks and we saw several fish passages installed. One of which, you can see in the clip below, is often times filled in by a beaver dam. Through no fault of its own, the beaver hears flowing water and sees a great spot to make a dam on a human-modified substrate and conflicts occur. Again, if team human was not perturbing the system there would be no need for a fish passage up a concrete rampart and therefore no need to demolish the beaver dam. Oh team human, why can't you play fair?


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Thursday, March 20, 2014

Beaver/Salmonid Workshop Part I

It was quite the explosion of beaver supporters crossbred with salmonid workers today at the workshop for beaver/steelhead & salmonid interactions. What a fine pedigree of people attending displaying a wealth of knowledge at the intersection of all things anadromous, finny, furry, and buck-toothed. The building itself is the spanish villa styled senior center on the waterfront in beautiful Santa Barbara CA. Only a stones throw from where I live in Oxnard CA I was able to drive there. Lucky me as others attending came in from as far away as Massachusetts!! This was the first workshop of its kind put on by the salmonid restoration foundation and as far as I know the first seminar/workshop highlighting the juncture of beaver and anadromous fish. 

The first talk was by Rick Lanman (Institute of Historical Ecology), who spearheaded the recently published paper on the historic range of beaver in California. It was a well executed speech, also getting into some of his past work on beaver dams in the high sierra. One thing that was new to me was how important the steel trap was in extirpating beaver. And this extirpation, Lanman maintains, was not always committed by English and Russian fur trappers- but by the native Americans who got access to this deadly new technology. Rick also went further into the interesting semantics that for so long confused historians looking at the historical record for beaver clues. Spaniards referred to beaver as las nutrias- Spain itself having had its population of beaver long extirpated -not as Castor. The Spanish wrote of nutrias marinas- sea otters -and fresh water nutrias- which you might think implies fresh water otters -except that the record for fresh water North American river otters south of Monterey Bay is... nonexistent, and that leaves you with beaver. Not to mention the fact that these nutrias were described as dam builders. Well done Rick and coauthors, a job well done.

Eli Asarian (Riverbend Sciences) dovetailed into a discussion on the current distribution of beaver in California. He is a coauthor on the Lanman paper and works primarily in northern Californian watersheds. Eli presented loads of nice pics on beaver dams as well as presenting some data on juvenile coho/steelhead using beaver ponds as rearing ponds. Eli also has done some crucial work spearheading beaver mapper, an invaluable tool allowing scientists and citizens to document beaver sightings and document their expansions. He also hinted at some new and exciting work on beaver and salmonids coming down the pipeline!! Good job Eli!!

Next up was Heidi Perryman of Worth a Dam and Martinez Beavers. I also like to call her the CNN of beaver because she is a bit of touchstone for all things beaver. Her presentation was basically a summary of the 6 years of citizen science that she and her group have been doing in Martinez CA. I like that she took a stand and said we are not tagging these beavers. Plenty of good observational science can be accrued without alien abductions, I mean tag and release studies!! Thanks for coming down and presenting Heidi!!

The next speaker was Michael Pollock, a heavy hitter in the world of beaver/salmonids and is one of only a few published authors looking at this interaction. He gave a nice review of our knowledge of the interaction of beaver dams and salmonid passage and basically concluded... more research is needed. How very sciency of you Michael, just kidding- his talk was basically favorable to beaver and salmonids cohabiting, especially coho and steelhead being the best jumpers. But in addition to jumping salmon can swim over and around dams with appropriate flows. He also made a very pertinent statement regarding watershed health to paraphrase: the more complex, the more difficult to measure a habitat is, the healthier it is. Chew on that one kiddies. For me that means if a watershed has deep quiet pools, fast ripples, side channels, ox-bow lakes, deep parts, shallow parts all jumbled about and mixed together that is a good system. And beaver can help in those regards. One thing that Pollock stated that did get my attention is the concern that beaver dams might hold-up or delay downstream migrating smolt. While in some populations/species I can see why this is a concern, in the case of the southern steelhead, a unique population of steelhead and the most behaviorally plastic of all steelhead I think that this presupposition warrants further analysis. Let me elaborate: It is now generally understood that downstream migrating southern steelhead get through the main channel, which may usually go dry in socal, and arrive at the lagoon/estuary often times blocked from the ocean by a beach berm. They then come to size in the relatively rich feeding ground of the estuary and move into the ocean when the 
time permits. However, as recently happened in the santa clara estuary, if these estuaries are breached prematurely steelhead might be left high and dry. My point is that if downstream migrating smolt found a beaver pond to their liking- that gives them another option besides the estuary to grow up in. Something to think about...

Next up was Tim Robinson, MC for the event, and also the man tasked with balancing the needs of the citizens of Santa Barbara county, Cachuma reservoir, fish, agriculture, difficult landowners, invasive species, and beaver on the Santa Ynez watershed. His was the most guarded speech as goes the benefits of beaver to highly modified, Mediterranean climate watersheds. From his perspective I can see where he is coming from. The Santa Ynez river is a little strange in that Lake Cachuma, a man made reservoir, effectively cuts off half of the watershed to steelhead. What is left is the main channel and several tributaries, most notably Salispuedes creek as steelhead habitat. Due to the inability of steelhead to get up to the majority of their historical spawning grounds Tim and the Cachuma water group are trying to maintain the main channel of the Santa Ynez as a habitat for steelhead spawning. And as you may know this is not really how the southern steelhead works- the main channel is simply the avenue used to reach tributaries for spawing. So criticisms that beaver dams spread non-natives, warm the water, or spread sediment in the main channel really fall a little flat in light of the fact that steelhead don't treat the main channel as the spawning grounds- they want the cooler mountain tributaries. Secondly the other indictment on Santa Ynez river is that flows are not reached that blow out the beaver dams. Again, in this modified system, Lake Cachuma absorbs a lot of these flows so that the full potential fury of this river is never reached as it would if the dam was not there.

Anyways I will continue with my thoughts on some more speeches and video shortly. Including two more speeches and the Santa Ynez beaver tour!!!


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Monday, March 17, 2014

Conservation/Restoration in the 21st Century: More Complex and Critical than Ever

Blogging is a funny and interesting thing. One thing that I have noticed is that when you plug into a community of like-minded bloggers that overlap in subject matter an interesting phenomena occurs where a type of hive mind, or congruence of ideas develops. It is almost like some type of subconscious  meta-brain is at work creating a general thrust of thought in a significant direction. I have experienced this on my paleontology themed blog Antediluvian Salad several times and a similar event occurred with regards to conservation/restoration efforts spurred on by two blogs I follow closely.

The first blog is one that, if you follow this blog, you no doubt know of: Heidi Perryman's Martinez Beavers- the veritable CNN of all things beaver. The post I have in mind is from several days ago entitled Save-Everythings, Save-Somes and Save-Ours. A very interesting post and one that touches upon a lot of crucial issues in contemporary conservation/restoration work. Starting with a critique on how certain groups misunderstand/misapply beaver devices/trapping Heidi dovetails into a discussion on the difference between Save-Ours, Save-Somes, and Save-Everythings and how her group has transitioned between these different groups in her beaver saga. At first she was a Save-Ours, concerned with the Martinez beavers. When this group was safe she transitioned to more of Save-Some until now she calls herself "a hugger who has learned to camouflage herself as a Save-Some." Of the three groups, Heidi maintains, it is the Save-Everythings that face the most stony path- they face a daunting challenge, ridiculed for the most part and said to be "disconnected" from the real world. Scientists and professional wildlife/forestry agents will almost unanimously align themselves with the Save-Some line of thought for fear of the Hugger label. A particular telling example Heidi recounts when a colleague sent Heidi video of a beaver dam being blown up and Heidi responded emotionally to which said colleague replied "that I should be able to laugh at these things. I shouldn't act so upset or people would accuse me of being a hugger." 

As a little ironic aside, the disparaging phrase of hugger derived from the phrase tree-hugger, popularized as an insult to old-growth redwood activists, is maybe not applicable towards beaver defenders. Because beaver, you know, are chopping down all those beautiful trees remember (wink, wink)?

The other post is one from Rick Merill's Coyotes, Wolves and Cougars...... forever! blog- a very prolific blog emphasizing predator rewilding/conservation in North America. Rick wrote a very telling and illuminating piece on conservation but be forewarned the second part of the piece is very disturbing and graphic: link. The first half of the post is timeline of some of the major milestones in conservation law for this country- largely bipartisan and largely popular when enacted. The second half of the post details an undercover probe into the coyote/wolf derby of Salmon, Idaho. Posing as hunters in the competition themselves the writers document a community beset with predator eradication, xenophobia, racism, gun-worship, anti-government, anti-liberal, and anti-HUGGER sentiment is brought to light. The community as a whole appears complicit in illegal hunting and trapping, as well as killing wild canids as painfully as possible. The ironically titled, Idaho for wildlife, sponsors the event and booooy do they have a dozy of a website, essentially just a shill for predator eradication with loads of self-citations and just bologna.

Here are some depressing excerpts:

Hunting for food is one thing, and in some cases
 hunting helps to keep overabundant species like
 deer in ecological check. But the reason we have too
 many deer in the US in the first place is simple: the
steady decline of big predators like the mountain lion
 and—you guessed it—the wolf. The fact is that we
 need wolves in ecosystems. So why a killing contest
 to rid the land of them?
After digging into the wolf-hate literature featured on
 Idaho for Wildlife’s website, I wondered whether the
 residents of Salmon were looking to kill wolves out
 of spite. They hated these creatures, and I wanted
 to understand why.
Besides killing wolves, one of the group’s core
 missions, according to its website, is to “fight against
 all legal and legislative attempts by the animal rights
 and anti-gun organizations who are attempting to take
 away our rights and freedoms under the Constitution
of the United States of America.” The website also
suggested that media coverage of the event was
not welcome. The only way I’d be able to properly
 report on the derby, I figured, was to go undercover
 as a competing hunter. So I showed up in Salmon
 a few days before the event, paid the $20 sign-up
 fee, and officially became part of the slaughter.
Going further into the belly of the beast that is the Salmon predator derby:

“Gut-shoot every goddamn last one of them wolves,”
 Cal told us. He wished a similar fate on “tree huggers,”
 who, in Cal’s view, mostly live in New York City.
“You know what I’d like to see? Take the wolves
 and plant ’em in Central Park, ’cause they impose
 it on us to have these goddamn wolves! Bullshit!
 It’s said a wolf won’t attack you. Well, goddamn,
 these tree huggers don’t know what. I want wolves
to eat them goddamn tree huggers. Maybe they’ll
 learn something!”

We all raised a glass to the tree huggers’ getting
 their due. I fought the urge to tell Cal that I live in
New York part-time, and that in college Natalie
trained as an arborist and had actually hugged
trees for a living. Her brother, who is 31 and
studying to be a lawyer in Boise, Idaho, had warned
 me about the risks of going undercover when I
 broached the idea over the phone. As a representative
for the nonprofit Western Watersheds Project, which
has lobbied for wolf protections, he’d attended numerous
public meetings about “wolf management” in communities
 like Salmon. “Salmon is the belly of the beast,” he told
me. “There is not a more hostile place. It’s Mordor.”
Brian’s former boss at the Western Watersheds Project,
 executive director Jon Marvel, has received death threats
 for speaking out in favor of wolves and against the
 powerful livestock industry. Many pro-wolf activists
across the American West, especially those who have
 publicly opposed the ranching industry, have reported
similar threats and acts of aggression—tires slashed,
 homes vandalized, windows busted out with bricks in t
he night. Idaho for Wildlife’s opinion on the situation is
made clear on its website: “Excess predator’s [sic
] and environmentalists should go first!”

Despite the "overpopulation" of wolves in Idaho not a single wolf was killed and only one seen in the derby, 21 coyotes killed. And with the delisting of wolves in several states peer reviewed science has been critical of this decision.
Now with these two blog posts in mind I want to go a little further. Beaver and wolf are both emblematic and native species to much of North America. Although one is a predator and one is a herbivore they both play pivotal roles in the ecology and landscape to which they are native. Both have attributes of a keystone species. They are both territorial and will expand into new territories when capacity is met. Both species have been largely exterminated from large areas of their former range. And both species are rife with accounts of pseudo-science, half-truths, and assertion science. And both species spell out some of the significant battle-lines drawn in how North America approaches its wildlife and wildlands.
What is most interesting to me is how the wolf has become a symbol of government over reach. How frustration on how this county is run, the role of government, is making a pariah out of recovering wolves. It is not too hard to imagine how beaver restoration can befall a similar fate.
And it is here that I want to go back to the Perryman post on what level of conservation do you support. Are you a middle of the roader Save-Some or do you want to take up the difficult task of Save-Everythings? 
Let us look at this question from the perspective of watershed health, specifically the beleaguered watersheds of California and specifically southern California which is our main subject. Hammered by diversions, dams, invasive species, agricultural and urban withdrawals, runoff and pollution- it is hard to call the damage done to these watersheds "middle of the road". Following from this, I argue, the solution to rehabbing these systems should not be "middle of the road" and therefore befitting more of a Save-Everything approach than a Save-Some approach. If we take the southern steelhead as a proxy for the health of the watershed, and these populations are conservatively 1% of their former population- then a middle of the road Save-Some approach is clearly not appropriate to this level of devastation. 
The point of a Save-Everything mindset is not that you will actually, you know, save everything. We will probably never see the historic level of steelhead, 10,000 or more strong, in our rivers. We will probably lose some species that are very near to extinction or extirpation- no matter how hard we strive for restoration. My point is that a middle of the road, Save-Some approach, is not doing the job and has not done the job in our watersheds. Unfortunately, for fear of being called a name- a Hugger -people in the know, people who know the science- DFW, game wardens, even conservationists - are always a little tentative to get too radicalized and go to the Save-Everything camp. Big business is always going to find it's voice. Politicians- depending on who they are trying to appeal to -are always going to find their voice. Will restoration ecology/conservation find it's voice? Will it take a back seat to other interests or insist on riding shot-gun?
Business and industry come and go. Money comes into a place and moves on. Look at Detroit. But if you let significant economic interests lay siege to the lifeblood of any landscape- it's water -then after that industry moves on, and they always do, now you are left both jobless and with a poisoned landscape. 

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Saturday, March 8, 2014

The Levee Broke... Beaver Historically Native to Most of California

Led Zeppelin- When the Levee Breaks (Play Loud)

If it keeps on raining the levee is going to break....

Yes what started as a drip, then a trickle, growing into a flow, is now a torrent. When I first started this blog there was the groundbreaking work on beavers in semiarid eastern Oregon to rehabilitate streams and steelhead/salmon habitat: Cheap and Cheerful Stream restoration with Beaver?  Drought stricken New Mexico decided to get proactive about a comprehensive statewide beaver management program. Then there was the awesome and timely paper on beaver ecology, management, and conservation of beaver in dryland stream habitats (Gibson/Olden 2014). The devastating California drought is waking people up about water conservation. Now there is huge interest in the salmonid/beaver workshop in Santa Barbara- the event ultimately selling out (for which I had to pull some strings just to get a pass myself). And now finally the paper which I have been waiting for for well over a year:

Current and Historic Range of Beaver in CA. CDFW Lanman et al

The Historical Range of Beaver (Castor canadensis) in Coastal California: A Review of the Evidence
(Christopher W. Lanman, Kate Lundquist, Heidi Perryman, J. Eli Asarian, Brock Dolman, Richard B. Lanman, Michael Pollock) California Fish and Game 99(4): 193-221 (2013)

Yes, that levee just broke. If you thought beavers in southern California is crazy talk, that there is not enough water for them or suitable habitat, that they will harm steelhead- well time to just think again and get yourself on the right side of history. The beaver zeitgeist is here and is not slowing down.

From the discussion section of the paper:

There has been a tendency to underestimate the influence of beaver on ecosystems
(Pollock et al. 1994). The presence of beaver has been shown to increase bird, fish,
invertebrate, amphibian and mammalian abundance and diversity (Naiman et al. 1988, Rosell
et al. 2005). As an integral part of the ecosystem of historic California, beaver may have
benefitted many threatened species. Colonization of southern California streams by beaver is
associated with increased riparian habitat, especially dense shrubby willow, which is critical
habitat for federally endangered southwestern willow flycatcher (Empidonax traillii extimus)
(Finch and Stoleson 2000) and least Bell’s vireo (Vireo bellii pusillus) (Muller-Schwarze
and Sun 2000) populations. There is evidence that beaver dams provide important refugia
for endangered California red-legged frogs (Rana draytonii) (Alvarez et al. 2013) and
western pond turtles (Actinemys marmorata) (Alvarez et al. 2007, Lovich 2012). Similarly,
beaver ponds and bank burrows appear to provide refugia for endangered tidewater goby
(Eucyclogobius newberryi) (USFWS 2005). In a historical ecology study of the San Gabriel
River in southern California, it was estimated that since 1870, 86% of historical wetlands
have been lost especially in the lower floodplain (Stein et al. 2010). In contrast, in the tidal
Copper River delta beaver activity has been shown to increase freshwater surface area and
to prevent seasonal drying of the floodplain (Cooper 2007). Allowing beaver to recolonize
their historic range could reverse the ongoing loss of wetland habitat in California’s coastal

Documenting that beaver were historically extant in California’s coastal streams
may have important implications for declining salmonid populations. Pollock et al. (2003)
reviewed reports of beaver “perennializing” formerly seasonal streams, and Tappe (1942)
noted summer flows in several streams in northern California increased after beaver
colonized upstream reaches. Gallagher et al. (2012) reported on limiting factors for coho
salmon (Oncorhynchus kisutch) populations in coastal northern California streams and
concluded that winter habitat was critically important, recommending adding substantial
amounts of large wood to increase pool habitats, improve stream shelter in high winter
flows, and reconnect the stream to floodplain habitats. Beaver impoundments also increase
winter habitat, and whereas large woody debris may be associated with coho salmon smolt
production (SPP) of 6-15 individuals, SPP per beaver dam ranges from 527 to 1,174 fish,
indicating that promotion of beaver populations may have an 80-fold more positive impact
(Pollock et al. 2004). Salmon from Alaska to Oregon have clearly evolved in sympatry
with beaver and these anadromous fish ascend coastal streams with beaver dams, the latter
often overtopped or breached by high winter flows. Coho salmon can jump dams as high
as 2 meters (Bryant 1984, Powers and Orsborn 1986). Gard (1961) showed that rainbow
trout (Oncorhynchus mykiss) can also cross beaver dams and in both directions, with some
accounts of trout crossing a series of 14 dams (Pollock et al. 2003). Hood (2012) reported
that beaver dams tripled juvenile Chinook salmon (Oncorhynchus tshawytsha) survival in
brackish tidal marshes in the Skagit River delta of Puget Sound. Today California’s coastal
beaver are widely regarded as the non-native survivors of twentieth century translocations,
and when they cause flooding problems or fell trees, depredation permits are often provided.
Understanding beaver as native to coastal ecosystems may impact this decision-making.

Fillmore Fish Hatchery. Rainbow Trout. author
Based on the results of our study, coupled with the recent evidence of historic beaver
in the Sierra Nevada (James and Lanman 2012, Lanman et al. 2012), and the long-established
nativity of beaver to the Central Valley, the Colorado River and California’s northern rivers
(Tappe 1942, Grinnell et al. 1937), we conclude that the historic range of beaver included
most of California, except the streamless portions of the southern deserts (Figure 4). We
consider the historic presence of beaver in the perennial streams in California’s deserts (e.g.,
the Mojave River) unverified, but highly probable, given their current presence in these
systems (Lovich 2012) and the historic and current presence of beaver in similar desert
streams in Arizona (Allen 1895).

Beaver Dam. Santa Ynez River. Author

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