Some Thoughts on Endangered Aquatic Species

Arivaipa Creek looking toward the canyon

Arivaipa Creek

Warning: This post will not be my usual happy, hooray for nature type post.  This one deals with a serious issue and may be considered depressing to some readers. Consider yourself warned.

The Zoological Society of London recently released a publication called Priceless or Worthless?  The World’s Most Threatened Species.  In spite of the fact that I absolutely hate the title (I don’t like to think of any species as worthless, no matter how few of them are left), I was eager to look through the document to see what sorts of invertebrates their list contained.  I was happy to see that several insects and other arthropods are featured, including a few damselflies, a few butterflies, a spider, a crab, a cricket, a bee.  I think it’s fantastic that so many invertebrates made the list as it means that people out  there care whether these animals live or disappear forever, and that sort of attention and love is rarely bestowed on the spineless creatures of our planet.  It’s sad that these creatures made the list in the first place, but it also means that they will get a lot of attention, and that’s a good thing.  Insects and their relatives get far too little attention when it comes to endangered and threatened species lists and it’s high time we started paying more attention to them.

bonytail fish

Bonytail chub, and endangered native fish in Arizona

Looking at the list as a whole, however, got me thinking.  Yes, there are several insects on the list, but I noticed something else: there are a lot freshwater species  listed overall.  This wasn’t especially surprising as I know how specialized aquatic organisms can be, how they can be so incredibly picky about where they live that it puts them at risk when anything in their environment changes.  For example, amphibians have been on the decline for years.  Scientists have variously pointed to habitat destruction, pollution of aquatic habitats, increased UV radiation passing through a thinner ozone layer, climate change, and the recent epidemic of chytrid fungus throughout most of the world as explanations for the decline.  In some areas, a combination of these factors have even led to extinctions of amphibian species and may lead to more in the future.    Amphibians are incredibly sensitive to changes in their environments, and that’s not really a good trait to have in a changing world.

Tree frog

Tree frog – adorable!

But frogs are big, showy animals that a lot of people like.  Many aquatic insects are likely similarly sensitive to changes in their environments, but we know so little about them we can’t even describe the distribution of many species with any sort of accuracy.  One species of riffle beetle was described from specimens found only in a single stream in the Chiricahua Mountains of southern Arizona, but is that really the only place they live?  Is a population still found there?  And what about the big Horseshoe 2 fire there two summers ago that burned a huge part of the mountain range?  Riffle beetles generally require clear, cool, flowing water to survive and that one population was likely incapable of surviving ash flows.  Has that species gone extinct?  Does anyone know?

Priceless or Worthless also includes an 8-page list of species that have already gone extinct.  Among the relatively small handful of insects that are known to have disappeared (and there are half as many insect species listed as birds, in spite of being a much more diverse group), you see the usual trends: mostly butterflies and moths with some beetles and several aquatic insects.  The latter include caddisflies, mayflies, and stoneflies, insects that are generally sensitive to pollution, habitat loss, and other changes in their habitats.  However, that list includes only species that we know have gone extinct.  How many insect species have disappeared without our even noticing?  I think we’d be lucky to observe the disappearance of most species.  And then there are the untold millions of insects that we haven’t even cataloged and named.  There are so many insects out there that it’s simply impossible to monitor them all and we know very, very little about most species.  That, combined with the public relations problems that insects typically face, means that insects are often ignored when endangered species lists are compiled.  It is likely that countless species have gone extinct without ever even drawing our attention.

Glossosomatid caddisfly

Glossosomatid caddisfly

Looking through the list of the 100 most threatened animals and seeing some aquatic insects and other aquatic organisms there gives me hope that people do care about these species and are working to protect them.  That’s a step in the right direction.  But are we going to be able to save them?  Consider this: the human population topped 7 billion people about a year ago.  We added 1 billion people between 1999 and 2011.  That’s 1 BILLION more people who needed places to live.  That’s 1 BILLION people who needed water to drink.  That’s 1 BILLION people who depended on crops that require watering.  That’s 1 BILLION people who produced more waste, a lot of which ended up in our waterways.  Many of the world’s great rivers are already so badly polluted that they are becoming virtually unusable by humans (the Yangtze River, for instance).  Many of our rivers have seen severely depressed flow over the last 100 years such that even mighty rivers like the Colorado River, once a lush and vibrant river along its entire length from the Colorado Rockies to the Gulf of California, only rarely reach the ocean now.  We humans are in direct competition with aquatic plants, animals, and other organisms for aquatic resources.  When it comes down to a choice between us or them, does that rare caddisfly living in one stretch of one mountain stream have any chance as the human need for water advances into its habitat?

caddisflies

Caddisfly adults, aquatic as larvae

If you haven’t noticed from my writing on this blog, I love this planet.  I try to stay positive about things, think that we can make things better.  For the most part I focus on all the positive, wonderful things in our world.  But, I also recognize that my favorite insects, the ones that live in my favorite habitats, really are at risk of extinction.  I know I would gladly give up a golf course to save a caddisfly species when both required the water.  I would gladly forego a lush, green lawn to ensure that my unborn children have a chance to see a rare stonefly in a local stream.  I like to believe that a lot of people would do the same if they recognized the risk these animals face (that’s one of the seven impediments to invertebrate conservation I discussed back in January).  However, if we ever have to decide between getting enough water to drink and saving that caddisfly or that rare stonefly, it’s unlikely to end well for the insects.

Sunset at Los Fresnos

Sunset over lake at Los Fresnos

So what can I do about it?  Well, I’m going to keep blogging for starters.  Very few non-scientists even know aquatic insects exist, so getting information about aquatic species out there into the world is a good thing to do.  I can educate people through my job and encourage people in my area to conserve water.  I will continue photographing aquatic insects because I believe people are less inclined to let a species go extinct if they can attach a face to it than if it remains a total stranger.  I can continue to make changes in my own life to help alleviate some of the stress on our aquatic habitats.  I truly believe we can coexist with the species around us with proper education, planning, and awareness of how our actions impact our world.  And indeed, Priceless or Worthless ends on a similar note, describing some conservation successes, species that have recovered after nearly going extinct.  There aren’t any insects on that list, but there have been some successes in saving butterfly and dragonfly populations from extinction over the last few years that weren’t featured.  It’s my hope that someday I will see an insect on that conservation success list – and maybe it will even be aquatic.

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Unless otherwise stated, all text, images, and video are copyright © C. L. Goforth
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Things You Can Do To Promote Invertebrate Conservation

stonefly adult

Stonefly

Yesterday I discussed a paper that covered 7 impediments to invertebrate conservation, problems that prevent invertebrates from being considered worthy/fundable conservation targets.  The authors of that paper ended by saying that it all ultimately boiled down to public perception, that until people understand that invertebrates play an important part in our world, we’re not going to see any changes.  That got me thinking and I came up with a list simple ways that everyone can help save invertebrates.  I’m going to split this up into two sections: things that scientists can do and things non-scientists can do.

Simple Ways Scientists Can Promote Invertebrate Conservation

There is, I believe, a huge gap between scientists and non-scientists.  Scientists often have a hard time communicating with the public because they are so engrossed in their work that they sometimes forget how to talk to people who don’t work on similar topics.  We scientists also have our own language, Science, that works smashingly well in scientific journals, but doesn’t translate into plain English (or other languages) very well.  It’s no wonder that people don’t appreciate invertebrates when the people who study them seem incapable of sharing what we know with non-scientists.  But there are ways we can help bridge the scientist/non-scientist gap!  Some suggestions:

Crab spider

Crab spider, species unknown

1) Use social media.  People are getting more and more information about their world from the internet.  Guess what:?  YOU can be one of the people that provides that information!  Start a blog about your invertebrate research so that people can learn about what you do and why it is important.  Twitter is a surprisingly good source of science news – start contributing to the conversation!  Why not offer to write guest posts for other bloggers/media outlets?  By making the public aware of your research and by explaining it in terms that anyone can understand, you can really help boost the public image of invertebrates.

2) Do talks/lectures/events aimed at educating the public about invertebrates.  Scientists sometimes have a hard time sharing what they know with the world outside.  Try getting out of the lab and talking to non-scientists every now and then!  Give a lecture for a garden club.  Do an outreach program at a school.  Set up an educational booth at an event, or create your own event to celebrate invertebrates!  Answer a few questions if a nature show calls and asks for information.  Doing even a few of these sorts of things a year will help!

Spotted orbweaver spider

Spotted orbweaver, Neoscona crucifera

3) Develop citizen science projects.  Nothing helps people understand the importance of your research like participating in it.  I’ve already discussed the value of citizen science in a recent post so I won’t rehash everything again here, but note that amateur scientists/naturalists have a lot to offer if you only give them an opportunity to contribute.  Citizen science.  Try it.

4) Develop educational resources for the public, especially K-12 students.  Guess what?  People WANT to learn about invertebrates!  Providing educational information online can help them appreciate the value of invertebrates in their lives.  People want to know about the work you do, but how can they learn about it if you don’t make the information available somewhere they can actually access it?  And you know who really loves to learn about insects?  Kids!  Helping young children understand the role of invertebrates in the environment and teaching them to appreciate insects is a fantastic way to do a little invertebrate PR!  Hook ’em while they’re young and they’ll also go on to become people who support conservation and invertebrate research funding as adults.

SIMPLE WAYS Non-SCIENTISTS CAN PROMOTE INVERTEBRATE CONSERVATION

Leaf cutter bee

Leaf cutter bee, Megachile sp

You don’t have to be a scientist to help prevent invertebrate extinction!  Here are some things non-scientists can do:

1) Get to know your area.  Go outside and pay attention to what you see.  People who carefully observe their local areas are in the best position to notice when something is changing, and scientists can’t be everywhere at once.  Consider yourself a scientist’s eyes and ears on the ground!  By simply getting out, walking around, and recording a few observations, you can potentially make an important contribution to invertebrate conservation.  The exercise and fresh air will do you good too!

2) Ask questions.  Don’t know what an invertebrate you observe is?  Ask someone who knows!  Snap a photo and submit it to BugGuide.net for a free identification.  Talk to the entomologist at your local extension office.  Got a land-grant university in your area?  They likely have collection curators who are expected to field calls from the public, so feel free to call them!  Consult field guides, especially ones specific to your area.  Get involved with citizen science projects and talk to the project leaders.  Learn learn learn – and ask if you can’t figure out the answer to a question yourself.

Hemiphileurus illatus beetle

Beetle, Hemiphileurus illatus

3) Keep records!  Memory is a troublesome thing.  Unless you have a photographic memory, chances are you’ll start to forget details soon after you observe something.  Jotting down notes, snapping a few photos, keeping a nature journal – these things will help you remember what you see in much greater detail.  You’ll be able to accurately track which species you see when and where and compare past notes to new observations.  That way, you can see if it really is weird, for example, to see a flower blooming in January or a fairly routinely event.

4) If you notice important changes in your area, share your findings.  If you pay attention to the things around you, keep records, and have proof that something is changing the invertebrate communities in your area, consider sharing your findings.  Local conservation groups will often be interested in what you have to share, so give them a call!  Or call your extension entomologist or your land-grant university collection curator.  If what you’ve observed is nothing to worry about, they’ll tell you.  But if something is happening  to the invertebrates in your area, they can help get the ball rolling on new conservation efforts.

Long jawed orb weaver spider

Long jawed orb weaver spider, Tetragnatha sp

These are just some of the many ways that everyone can participate in protecting invertebrates and ensuring that our world functions properly well into the future.  If you’d like to contribute any additional ideas for ways scientists and non-scientists can help conserve invertebrates, please leave a comment below.  I’d love to hear from you!

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Unless otherwise stated, all text, images, and video are copyright © TheDragonflyWoman.com

Science Sunday: Impediments to Invertebrate Conservation

Hadrurus arizonensis giant hairy scorpion

Giant hairy scorpion (Hadrurus arizonensis)

Back in October, the New York Times Green Blog featured a post about a paper that had been recently released covering seven major reasons why invertebrate conservation isn’t garnering as much attention as it should nor being acknowledged as an important use of conservation resources.  I liked the blog post, so I recently read the paper that it was based on.  I think the paper makes some great points, so I’d like to take you through it here.

Insects and other invertebrates make up the majority of the described species on the planet Earth.  About 80% of all described species (this includes everything – plants, mammals, bacteria, fungi, insects…) are invertebrates.  Beetles alone make up 25% of described species and outnumber vertebrate species ten to one.  Clearly, invertebrates are an important part of the world.  They also perform an enormous array of environmental functions, from decomposing organisms and fixing nitrogen in soils to controlling pest species and processing leaf materials in streams to begin the nutrient cycling that drives freshwater ecosystems.  The services invertebrates provide are important for a wide range of other organisms.  Thus, it is important that we consider invertebrates and their role in biological and chemical processes when making plans for the conservation of organisms.

Water scorpion, Ranatra quadridentata

Water scorpion, Ranatra quadridentata

However, that’s not what’s happening.  Invertebrates are widely ignored by conservationists in favor of the showier organisms, the warm and fuzzy creatures that make people say, “Awwww…” before reaching into their pockets to fund research.  Far fewer people who say, “Awwww…” and shell out a few bucks to protect a parasitic wasp, a spider, or an aquatic beetle.  In fact, many people would probably rather let an insect species go extinct than pay to protect it.

This sort of attitude is also reflected in the endangered species lists, such as the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species.  These lists rarely include insects and other invertebrates so that the representation of invertebrates does not reflect their abundance and diversity in the natural world.  This is a problem, especially when you start to really think about the necessary services that invertebrates provide, the medical and research advances we’ve made based on invertebrate models (think fruit flies and C. elegans), and their the utility of invertebrates as indicators of ecological health.

Katydid

Katydid (I think this is the common short winged katydid, Dichopetala brevihastata)

Scientists recognize the value of invertebrates in the environment and are aware of the fact that invertebrates are often neglected when it comes time to conserve species.  Why, then, are there still so underrepresented?  Pedro Cardoso, Terry Erwin, Paulo Borges, and Tim New discussed seven reasons why these problems exist and recommend actions to solve them in their important paper.  Let’s go through each of them!

Problem #1: Invertebrates and the services they provide are not widely known among the public.  It’s hard to convince people that they should allocate funds (or at least support allocation of those funds) for invertebrate conservation when they’re not aware of the diversity of invertebrates or the valuable things they do to keep the world running smoothly.  Even worse, most people come to believe that most invertebrates are either pests or dangerous (neither is true) and fail to understand why anyone would want to prevent their extinction.  Solution: Cardoso et al recommend increasing awareness of invertebrates through media and outreach, a sort of invertebrate PR campaign if you will.  Even simply using common names when communicating with the public might be a step in the right direction.

Banded argiope, Argiope trifasciata

Banded argiope (Argiope trifasciata)

Problem #2: Politicians are largely unaware of the issues surrounding invertebrate conservation.  When our policymakers, the people who will ultimately determine the fate of research finding, are mostly unaware of invertebrate conservation issues, it’s hard to them to justify why invertebrates are important enough to deserve funding.  Solution: Educate the policymakers!  Working toward  better representation of invertebrates on the IUCN Red List and similar lists will also allow people to lobby on behalf of invertebrates to ensure that their conservation becomes a priority.

Problem #3: Basic taxonomic, ecological, and behavioral research is becoming increasingly understudied and underfunded.  It’s hard to determine which species demand our attention for conservation when we don’t even know what their role in the environment actually is.  Basic research helps answer these questions, but is becoming increasingly unpopular and funding for such work continues to decline.  Solution: Citizen science to the rescue!  Amateurs come across new species more often than you’d think and are able to provide useful data on distribution and abundance.  There are more non-scientists than scientists, so why not make use of hundreds of extra eyes and ears to cheaply answer some of the basic questions that are becoming hard to procure funding for?

Blue eyed darner, Rhionaeschna multicolor, flying

Blue eyed darner (Rhionaeschna multicolor)

Problem #4: Most species remain undescribed.  Estimates of the total number of invertebrate species in the world vary widely, but one thing is certain: we have probably only scratched the surface of invertebrate diversity.  According to Cardoso et al, a new invertebrate species is described every 35 minutes, but at that rate it’s going to take another hundred years or more to describe every species.  Just think of how many species might go extinct in that time!  Solution: Careful use of indicator species or surrogate species might be useful in applying conservation efforts to undescribed species.  Increased support for both taxonomic research and the speed of publication of new species descriptions will also help.

Problem #5: We don’t know the distribution of most species.  Describing a species is a start, but to protect it you need to know the extent of its distribution – where it actually lives.  Many species descriptions are based on 3-4 insects from a single location, so we don’t know the range of most species.  Solution: It is important that survey projects such as the Planetary Biodiversity Inventory continue to catalog and document life on Earth so that we know where species are actually located.  Online databases of distribution data such as the Global Biodiversity Information Facility will also help decrease the amount of time a researcher or conservationist must search for distribution information.

Problem #6: Changes in abundance over time and space are unknown for most species.  To conserve a species, it’s essential to know where that species is located, when, and how abundant it is.  We don’t, however,  have abundance data for most species.  Solution: By developing standardized sampling protocols, an effective biological inventory of an area can be undertaken by nearly any researcher for whatever purpose, yet provide information that is valuable to conservation efforts and other researchers.  Long term ecological and monitoring projects will also provide valuable information for conservation efforts.

crane fly side view

Crane fly (Tipula sp.)

Problem #7: Life histories and sensitivity to changes in the environment remain unknown for most species.  If we don’t know which ecological services a species requires or provides, it’s hard to develop invertebrate conservation strategies that will actually work.  Solution: Indicator taxa in an area might alert researchers and conservationists to problem within an environment (protect the environment, protect the species within it).  Determining which species make good indicators within an environment is a good way to start conservation efforts in an area.

Cardoso and colleagues identified seven impediments to invertebrate conservation, but they admitted that, in the end, it all boils down to one overarching issue: public perception of invertebrates.  We aren’t going to be able to solve any of Cardoso et al’s list of problems without the support of the public – support for invertebrates, support for science and research, support for conservation.  It is thus vitally important to get the public on board if we’re going to save invertebrate species from extinction.  And why should we save invertebrates?  I think Cardoso and his colleagues sum it up best: “Only by preserving all species and guaranteeing interactions and ecosystem services may we reach the goal of overall biodiversity conservation.”  And, ultimately, what’s best for invertebrates is best for us too.

Literature Cited:

Cardoso, P., Erwin, T., Borges, P., & New, T. (2011). The seven impediments in invertebrate conservation and how to overcome them Biological Conservation, 144 (11), 2647-2655 DOI: 10.1016/j.biocon.2011.07.024

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Unless otherwise stated, all text, images, and video are copyright © TheDragonflyWoman.com

Well-Nigh Wordless Wednesday: Spider and Young

I was involved with a conservation-centered biological survey of a Mexican ranch a few years back and I came across this spider as we toured around setting up sampling sites:

spider with young

A spider - with spiderlings!

I didn’t notice until I looked at the photos later, but the eggs were hatching while I was there and there were baby spiders everywhere.  Super cool – and such a spectacular animal!

(If anyone knows which spider this is, I’d love to know!)

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Unless otherwise stated, all text, images, and video are copyright © 2011 DragonflyWoman.wordpress.com

Notes From NABS Day 5

meeting logoPhysical, Chemical, and Biological Changes Along the Continuum of an Agricultural Stream: Influence of a Small Terrestrial Preserve

Well, I didn’t quite get this post done the day I meant to, but my day ended up being quite busy.  However, the NABS/ASLO joint meeting of 2010 is now officially over!  That means this will be my last NABS post until I go to another conference.  It’s nice to be back home!  Meetings are exhausting and melt your brain after a while.  They’re fun, but they’re intense – and I never get enough sleep.  No matter how much I enjoy a meeting, I’m always happy to get back home and sleep.  And, if I come away from the experience without any new communicable diseases, I’ll consider it a success.

I’m going to skip the Things I Leaned section for today and jump right into the last talk.  Today, my focus is a talk by Dr. David Houghton that was given on Day 3 of the conference.  Dr. Houghton is an entomologist and Associate Professor at Hillsdale College.  Hillsdale is a small liberal arts college (even smaller than the one I went to as an undergrad!) and Dr. Houghton is in the department of biology there.  Sadly, there aren’t all that many people from these sorts of schools at most of the meetings I go to.  This is doubly sad because Dr. Houghton’s presentation was really interesting and made some excellent points.

In the area in southern Michigan where Dr. Houghton completed his study, the streams used to be surrounded by a wide strip of dense vegetation (the riparian zone).  The area is now an agricultural region.  This means that, rather than large trees and plants that require a lot of water filling the space adjacent the streams, the native plants have been removed and the agricultural fields go right up to the banks.  This has several implications.  The lack of trees means the water is warmer than it was before the trees were removed because there isn’t as much shade on the water.  A lot of chemicals such as pesticides and fertilizers end up in the water any time water flows over the fields and into the streams (i.e. during rains, heavy irrigation, etc).  Those chemicals decrease the water quality, which in turn impacts the plants and animals that live in the water.  Overall, the water quality decreases and with it the number of species that can live in the river.

In general, this situation isn’t good for the stream or any of its biota.  The river needs the forested areas for everything to work properly.  Removing the riparian area means that things in the river change and the “health” of the river goes down.  Stream health is a somewhat vague concept that I don’t want to get into here, but it is essentially a measure of how close to naturalistic conditions an ecosystem is.  Dr. Houghton’s talk began with this introduction.  Then he asked a question: are the small forested areas that are still available along southern Michigan’s streams capable of improving the water downstream so that the area downstream more closely resembles conditions without the influence of agriculture?  This has important implications for conservation of aquatic species.

Dr. Houghton’s study was conducted in the St. Joseph River in southern Michigan.  Like other rivers in the region, the St. Joseph has agricultural fields along the majority of its length with small forested areas near the headwaters.  In particular, Dr. Houghton was interested in one section of the river that had a small terrestrial preserve where the riparian area remained intact.  The river running through the preserve looked better than the area upstream, so he thought the water flowing through the area might be improved such that insects downstream of the preserve would fare better than the insects above the preserve.

To study this, Dr. Houghton chose six sites in the St. Joseph River from which he collected water and insect samples.  Two sites were above the preserve, two were within the preserve, and two were further downstream.  He measured several parameters of the water itself, including the temperature, dissolved oxygen, pH, and conductivity (effectively a measure of the amount of salt compounds in the water).  He also measured the insect populations by collecting adult caddisflies at light traps near the river.  Measuring the water parameters would tell him whether the water running through the preserve or downstream of the preserve was better than the water upstream of the preserve.  Because caddisflies are aquatic as larvae and live in the water for most of their lives, they are strongly impacted by water quality and are excellent indicator species.  Counting the number of individual adults and the number of species (also known as species richness) that came to the light traps would tell Dr. Houghton something about how “healthy” the river is.

His results were interesting.  There was no difference in any of the measurements of water quality Dr. Houghton collected above and below the preserve.  This meant that the river is an agricultural stream for its entire length and the preserve did not improve the water quality downstream.  There were two water parameters that improved within the preserve: the temperature (it went down) and the amount of dissolved oxygen (it went up).  These two changes can likely both be attributed to the amount of shade the river receives in the preserve versus the areas outside.  Shading the water causes the temperature to go down because less sun hits the water.  This in turn causes the dissolved oxygen to go up because cooler water holds more oxygen than warmer water.  However, once the water flowed back out of the preserve, the temperature and the dissolved oxygen went back to the levels seen above the preserve.  The preserve did not appear to be improving the water quality in the river.

Similar results were found using the insect samples.  Dr. Houghton found that 7 species of caddisflies made up 90% of all of the specimens coming to the light traps both within and outside the preserve.  These 7 species all feed in similar ways (they are collector-gatherers and they eat things that are floating in the water, like leaf particles and floating algae that are of the appropriate size) and have the same level of tolerance to pollution.  So, it appears that the majority of the caddisflies in the river were about the same throughout, again suggesting that the preserve didn’t do much to improve the quality of the river.

However, Dr. Houghton did detect one important difference between the caddisflies in the preserve compared to those outside: there were more species of caddisflies inside the preserve, so the species richness improved.  22 species of caddisflies were found only in area of the river where it flowed through the preserve.  Most of these caddisflies fed in a similar way (they are shredders, or insects that tear leaves and algaes into pieces small enough to eat – an important component of decomposition in aquatic systems) and the remaining species were ones that required cooler waters than those found outside the preserve.  None of these species were very abundant and in fact a few of them were represented by only a single specimen, but the species richness was definitely improved within the preserve compared to outside.

Dr. Houghton ended his talk with a question: is the river “healthier” because of the presence of the preserve?  He suggests that the answer to this question depends on what measure of health you are using.  The preserve clearly didn’t change the water quality so that the section downstream of the preserve was different from the area above.  If your measure of river health is whether the water quality and caddisfly populations downstream of the preserve are better than those above, then the preserve does not have any effect.  This could give some policy makers the idea that it’s okay to rip those last few preserves out, making space for more agricultural fields.  However, if your measure of river health is species richness, the presence of the preserve had a huge impact.  The river above and below the preserve had many fewer species of caddisflies than the area within the preserve.  Clearly the preserve is acting as a refuge for species that are unable to live in the more harsh conditions outside of the preserve.  Thus, if your goal is to maintain diversity in the stream, the preserve is very important.  In fact, building new forested areas along the water might further improve the diversity of the river even further.

I thought this talk was excellent.  It was a simple project, but it did everything it needed to accomplish.  Dr. Houghton’s talk also highlighted a couple of important points.  First, when looking for the biological impacts of a system on a species, you need to identify which measurements of health you want to use.  Second, it is good to consider multiple measurements of health within a system.  It would be tragic for any study to say that forested areas near a stream aren’t necessary because they don’t improve the water quality downstream.  I think what makes Dr. Houghton’s study great is the fact that he identified the changes in the species richness of the forested preserve, which showed that the preserve really did have an impact on the river system, if only in the area within the preserve.  It wasn’t exactly the one he might have expected or hoped for, but it does suggest that forested preserves are valuable to river systems and should be protected so that species diversity within the river is maintained.

And that wraps up the Notes from NABS series!  I hope you all enjoyed the glimpse into the research that is currently happening in the aquatic sciences and learned some new things.  Scientific conferences are an excellent place to gain new insights, think about things in new ways, or learn about things you’ve never even considered.  Hopefully I have passed some of these qualities on as they’re just too good to keep to myself.

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Posts in this series:
Day 0 – Introduction to the Series
Day 1 – Invasive Crayfish
Day 2 – Giant Water Bug Dispersal
Day 3 – Dragonfly Captive Rearing
Day 4 – Integrating Service-Learning Programs into College Courses
Day 5 – Impact of a Small Preserve on Stream Health

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Unless otherwise stated, all text, images, and video are copyright © 2010 DragonflyWoman.wordpress.com.