FISHBIO: Fisheries research, monitoring, and conservation

Ant snacks

Friday, May 17th, 2013

Ant nest

Ant eggs

During Southeast Asia’s dry season in January when the mango is ready to fruit, many people in the Mekong region rotate their dinner menu from wild fish to ant eggs. This is especially common for people in Lao PDR who depend on natural resources for food. Ant eggs are predominantly found in wetland areas with many trees or shrubs. Local people are experienced at finding ant nests and collecting the eggs, as well as simple ways to protect themselves from ant bites. After finding an ant nest, they first use the tip of a bamboo branch to check the quality of the nest, making sure the eggs are large and numerous enough to harvest, and have not yet developed into larvae. If the harvester approves of the eggs’ quality, he or she will hold a bamboo basket or water bucket hanging on a stick and shake the ant’s nest until the eggs fall into the basket.

Many ants will also fall into the basket or bucket with the eggs and may try to attack the harvester. One way to thwart them is to shake the basket repeatedly while walking. Another is placing branches into the basket, letting the ants walk on them, then tossing the branches into the bushes. Taking care not to kill the ants will allow them to lay more eggs. Some people who can afford it may buy tapioca powder to help them get rid of the ants. After harvesting the eggs, local people use them to cook various favorite foods, such as snakehead fish soup or leaf tree (Acacia) soup with ant eggs, fish salad with ant eggs, or simply fried ant eggs. Selling surplus harvest at the market can serve as an important source of income, particularly for women, and the eggs can also be used as fishing bait. Although fish are less abundant during the dry season, people can supplement their diet with ant eggs, then switch to harvesting wild mushrooms and bamboo shoots from April to June.

Insects play a vital role in sustaining food security around the world, according to a report recently released by the United Nations Food and Agriculture Organization. Worldwide, ants and their relatives (wasps and bees) are among the most commonly consumed insects, after beetles and caterpillars. Between 150 and 200 species of insects are consumed in Southeast Asia alone (see Little fishers). Although Westerners largely regard insects with disgust, the report emphasizes that in the rest of the world, insects are not a food of last resort – rather, people eat them by choice for their nutrition and taste. Food can take on many forms for the resourceful.

Categories : Mekong Basin

Tags : food security, insects, Lao PDR

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Attractive acne?

Wednesday, May 15th, 2013

Sacramento splittail

At first glance, the little raised dots on the head of this Sacramento splittail might resemble small pimples, but they are actually structures called nuptial tubercles: small, raised, and sometimes hardened bumps of skin. In many species, males develop these adornments during the reproductive season, often accompanied by brightened colors in their body and fins. Induced largely by hormonal changes, the appearance of the tubercles is clearly associated with reproduction, yet the exact role of these structures remains largely unclear. Some potential purposes include facilitating contact between individuals during breeding, providing tactile stimulation during reproduction, or being used as displays of dominance among males (e.g. Wendekind et al. 2008). Furthermore, some research suggests the amount and size of the tubercles may be an indicator of the individual’s condition and parasite load (Wendekind 1992, Taskinen and Kortet 2002, Kortet and Taskinen 2004). While no one has investigated whether this is the case for the Sacramento splittail, at least in some species a plethora of pimples signals maturity and health to available ladies.

Nuptial tubercles

Categories : Other Fish Species

Tags : reproduction, Sacramento splittail

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Don’t dump that fish

Monday, May 13th, 2013

Giant goldfish

All the world’s a fishbowl for an aquarium fish set free. As anyone whose pet fish has defied the odds can attest, aquarium fish are bred to be hardy survivors. Unfortunately, this trait makes it easier for the onetime pets to thrive in an unfamiliar place if their well-meaning owners decide to turn them loose. As an example, gargantuan goldfish pulled from the depths of Lake Tahoe captured public fascination earlier this year. Goldfish (Carassius auratus) are now found in most of California’s freshwater habitats, largely as a result of pet releases. Freed from the cramped confines of a fishbowl, goldfish may grow to well over a foot (40 cm) in length in the wild (McGinnis 2006). We at FISHBIO have netted a few massive specimens, like the one shown above, during a survey of Alameda Lake in Santa Clara County.

Although bright and unusual additions to the fish community, goldfish fortunately have not exerted significant damage on native species or habitats compared to other introduced fishes (McGinnis 2006). However, some ornamental species with voracious appetites have a dangerous potential to invade and alter new environments. Researchers at UC Davis released a report earlier this year that found 9 ornamental marine species have successfully colonized California waters. The list includes snails, worms, and crustaceans, but no fish as yet. However, with as many as 179 marine species passing through San Francisco in a single day for the aquarium trade, researchers are on alert for the escape of highly invasive fish species, such as the lion fish that has infested Caribbean waters largely unchecked. The phenomenon is a global problem: introduced ornamental fishes now swim through waters around the world, including the Mekong River (see The Mekong’s Amazon exotics).

The aquarium trade is just one route for non-native fish to enter California’s waterways. Introduced species already dominate California’s freshwater habitats (see graph below), and the majority were intentionally stocked by the California Department of Fish and Wildlife, formerly the Department of Fish and Game (Dill and Cordone 1996). An eight-year survey of the Sacramento-San Joaquin Delta yielded only 8 native species, and each was less than 0.5% of the total catch (Feyrer and Healy 2003). Other potential entry paths for introduced species include aquaculture, live seafood, and live bait species. While aquarium releases are far from the biggest threat to California’s native fishes, they are one more source of stress on highly altered ecosystems. So however much your fish looks like it longs for open water, do native fishes a favor and keep it in the tank. Delta species composition

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Categories : Fish Report, invasive species

Tags : goldfish, introduced fish, non-native fish

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Going custom

Friday, May 10th, 2013

Sanding a tabletop

We have featured the artistic creations of our fisheries technicians before, such as a gate with a riverscape scene or iron yard art (Artistic Outlet), but our design capabilities don’t stop there. When it came to furnishing the inside of our offices, we wanted something more original than typical particleboard tables and desks. We opted for concrete because of the flexibility it offers. With each new piece of furniture our designs become more creative, from a salmon silhouette embedded in the center of a table, to polished stones forming a meandering stream across a countertop, to painted steel trout cutouts adorning the base of a desk. We find we are constantly surrounding ourselves with reminders of the habitat and wildlife that we so enjoy working with.

The process of making a concrete tabletop starts with building a form out of melamine panels and sealing the seams and corners with silicone caulking. Inside the form we construct a wire or rebar skeleton to give strength to the thin concrete slab. Anything that we want to embed in the tabletop, such as wood, stones, or precast designs, is placed in the bottom of the form facing downward. We use a high strength concrete mix, like Quikrete® 5000, and combine it with water and coloring until it achieves a stiff, moldable consistency. The mix is then poured into the form and thoroughly tamped or vibrated to remove air pockets. We level the surface using a straight board (screed) to scrape off any excess mix. As the concrete begins to set, the surface, which will become the underside of the tabletop, can be smoothed with a trowel. After a week of curing the concrete slab can be turned over and the form removed. To get a smooth finish on the tabletop, we wet sand it with increasingly finer grit sanding disks, and then apply a water sealer. With some imagination and ingenuity, the design possibilities are limitless.

Categories : Fabrication

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A small obstacle

Wednesday, May 8th, 2013

Standing just 24 feet tall, Daguerre Point Dam on the Yuba River is a dwarf compared to most mainstem dams on California’s Central Valley rivers, which tower more than 500 or 600 feet. Though short in stature, the dam has become a sizable point of contention. Built at the beginning of the 20^th century to prevent mining debris from washing into the Feather and Sacramento rivers, the dam provides hydraulic head for irrigation diversions. Two fish ladders, one on each side of the river, were added in 1937 to allow salmon and steelhead access to the reaches between Daguerre and the Englebright dam upstream.

However, these fish passage facilities prove inadequate under certain flow conditions, and the National Marine Fisheries Service identified the dam as a major stressor to native anadromous fish populations in a biological opinion issued last year. Motivated by the aspiration of healthy salmon populations, various entities now advocate removing the structure, while others maintain the barrier serves as an important water diversion to the valuable local agricultural industry, and also blocks predatory fish (such as striped bass) from accessing salmonid rearing habitat above the dam.

A proposed hydropower project at this site recently stirred up new controversy over the future of the structure. Some see the dam as an outdated remnant of a time when the ecological impacts of development were not adequately considered. Concerned parties worry about continued and even additional fisheries impacts of the proposed hydropower facility, while advocates promise renewable energy, job creation, and improved fish passage. Such debate underscores that Daguerre Point Dam, despite its modest size, continues to be more than a small obstacle on the road to developing or restoring the Yuba River.

Categories : Water Use

Tags : anadromous fish barrier, dams, fish passage, Yuba River

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Secrets of the Mekong

Monday, May 6th, 2013

Last month brought a little limelight to FISHBIO’s international conservation program in Southeast Asia. The environmental and conservation news website mongabay.com interviewed our conservation director, Harmony Patricio, about the importance and challenges of studying Mekong River fishes, and about the recently launched Mekong Fish Network. “The world needs to realize that the Mekong is like the Amazon rainforest,” Patricio said of the river’s value. “It’s a global resource of incredible diversity and productivity.” A few excerpts from the interview are below. You can read the full article, accompanied by vivid FISHBIO photos, at mongabay.com.

Mongabay: How did you start working in the Mekong?

Harmony Patricio: So many people told me about the amazing fish diversity in the Mekong, how little is known about the lifecycles of most species, how important the fish are for the people living in the Mekong Basin, and how many big changes were on the horizon in Southeast Asia. I had a feeling that the Mekong would be the next hotspot for fish conservation… FISHBIO’s primary goal for our international work is to share our technical expertise in the places where it’s most needed. I felt like the Mekong region, and Lao PDR in particular, had a high need for technical capacity building to support local scientists.

Mongabay: What makes the Mekong River special in terms of fish?

Harmony Patricio: It has the second largest number of fish species of any river on earth, only after the Amazon River. More than 850 species have been described, and researchers estimate there could be over 1200 species. As a comparison, the whole state of California has about 67 freshwater fishes…What’s also special is how important the fish are for the people. There are over 60 million people that depend on the fish for protein and income, and the economic value of the fisheries is as much as $3.8 billion US dollars per year on first sale. So the river’s fish are highly diverse, feed a lot of people, and are worth a lot of money.

Mongabay: What do you hope to achieve with your new project, the Mekong Fish Network?

Harmony Patricio: The main goal of the Mekong Fish Network is to help people working with fish in the different countries of the Mekong Basin collaborate across national borders and share information so we can better understand what’s happening with Mekong fishes throughout the basin…We also hope to develop and implement standardized fish sampling methods throughout the basin to build a long-term monitoring program that studies how these fish populations change over time. No basin-wide program like this currently exists, and we need it if we want to achieve more sustainable fisheries management, conserve some of these rare or migratory species that are on the brink of extinction, and sustain the river’s productivity that people rely on for food and income.

Read the full interview>

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Categories : Fish Report

Tags : Mekong River

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Water or beer?

Friday, May 3rd, 2013

Travelers venturing abroad to regions like Southeast Asia will often get this piece of advice: Don’t drink the water. The warning comes with good reason: a number of diseases and illnesses can result from drinking contaminated water. The risk is higher in undeveloped areas, where a host of bacteria, viruses, and amoebas can lurk in water tainted with human or animal waste. Drinking contaminated tap water or eating food washed in it can wreak intestinal inconveniences like traveler’s diarrhea, or inflict more serious ailments like typhoid or Hepatitis A. Although many large Southeast Asian cities have modernized their sanitation and improved their water quality, when we travel in rural areas for our Mekong program, bottled water is usually our safest bet. Or it’s an excuse to sample another bottled beverage, like one of the local beers, and indulge in some cultural exchange.

But when safety is not an issue, a glass of tap water and a glass of beer are far from equal choices when it comes to the amount of resources they take to produce. Water is used throughout the beer making process, from growing hops and barley in the field, to brewing the beer itself, to packaging the bottles. This all adds up to create an item’s water footprint, which is about 20 gallons of water for a single glass of beer. Other drinks also pack hefty water footprints, such as 30 gallons of water for a glass of wine, or 35 gallons of water for a cup of coffee (see more at the Water Footprint Network). Whatever we choose to satisfy our thirst, we usually take a lot for granted about our drink in hand, like its safety or resource use. It’s something to think about before you take a sip.

Categories : Mekong Basin, Water Use

Tags : travel, water use

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Purple sea

Wednesday, May 1st, 2013

Spring blooms of lupine lend shades of blue and purple to otherwise featureless gravel bars and dry side channels in watersheds throughout California. Lupines, like many other legumes, don’t rely on soil nitrogen for nutrition. Instead, they have the ability to convert nitrogen gas from the atmosphere into ammonia, a biologically useful form. This ability allows lupines to thrive on infertile substrates, as well as enrich the ground and improve growing conditions for other plants over time.

Of the roughly 300 described species of lupine, the majority contain toxic alkaloids, and lupine poisoning is a common cause of livestock death in the western US. Despite this fact, people have used the bean pods produced by lupines as a food source for thousands of years. Popular in the Mediterranean since Roman times, the beans require a series of steps to leach the toxins before they can be eaten (such as soaking in salt solution or water, sometimes for several weeks).

In modern times, people have cultivated varieties of lupine containing reduced amounts of toxins, particularly in Europe. These beans are increasingly used in vegetarian cuisine and as a substitute for soy. Although we can’t reach for wild lupine as an easy, tasty riverside snack to munch on in the field, a spring bloom is a welcome sight in areas mostly devoid of color the rest of the year.

Categories : Miscellaneous

Tags : flowers, plants

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Surviving the south Delta

Monday, April 29th, 2013

One of the most intensive fishery studies ever conducted in California’s Sacramento-San Joaquin Delta culminated in 2011. The twelve-year study, known as the Vernalis Adaptive Management Program (VAMP), was a multi-organization effort designed to evaluate and improve the survival of salmon smolts migrating through the San Joaquin River Basin. The study investigated how salmon survival may be affected by changes in environmental variables such as river flow and water exports. A technical report summarizing the 2011 results is now available online.

FISHBIO collaborated with a number of other groups to tag, release, and track fish for VAMP (see Follow that fish). In 2011, a total of 1,895 Chinook salmon smolts and 2,195 steelhead smolts were surgically implanted with acoustic tags and released into the San Joaquin River at Durham Ferry. Fish can take multiple pathways through the Delta to the ocean, and the choice of route can affect their survival. Acoustic receivers were deployed throughout the Delta to calculate route-specific survival, and mobile tracking was conducted to determine where mortality was greatest. The two investigated routes were Old River, which heads toward water export facilities and fish salvage facilities, and the main stem San Joaquin River, which historically has had greater survival (Brandes and McLain 2001). Of the two routes that Chinook salmon selected in 2011, Old River had greater survival (4%) than the San Joaquin River (1%). The overall 2011 survival of 2% is consistent with other studies that show smolt survival has been declining in the Delta. Coded-wire tag studies between 1994 and 2001 indicated that survival through the Delta ranged between 15% and 50%. However, CWT and acoustic studies since 2003 have shown survival to be lower than 12% in the south Delta.

The development of acoustic telemetry technology has completely transformed our ability to study fish movement and survival. Biologists can now track the migration of individual fish throughout the Delta and even determine approximate locations where fish are likely eaten by predators. This has identified key mortality areas in the Delta and may help us understand why survival has declined so drastically over the last decade. The use of mobile tracking during the VAMP study helped identify locations where tags accumulated, presumably from predation. Three locations were identified as predation “hot spots”: 78 tagged smolts were lost at the the Stockton Deep Water Ship Channel on the San Joaquin River, 48 at the Grant Line Canal, and 37 in front of the trash racks at the Tracy Fish Facility in Old River. Previous years’ data suggests that the scour hole near the head of Old River and a railroad bridge in Stockton are also areas of high fish mortality on the San Joaquin River (Vogel 2010). Continued smolt outmigration monitoring studies and an increased effort to monitor non-native predator populations may help us solve some of the fish survival issues that have plagued the Delta for so many years.

This post featured in our weekly e-newsletter, the Fish Report. You can subscribe to the Fish Report here.

Categories : Fish Report, VAMP

Tags : Delta, Sacramento-San Joaquin Delta, VAMP

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Double duty

Friday, April 26th, 2013

Our multi-talented fisheries technicians lead a life of variety: when not surveying fish in the field or building equipment, they also serve as boat and vehicle mechanics. This includes regular maintenance and upkeep—or, in the case of the trailer shown above, retrofitting a piece of existing equipment to meet our needs. We had to make some modifications to a used trailer we bought for one of our boats to make it a better fit. This included lengthening the trailer tongue, mounting a new hitch, and repositioning the winch so its handle would not hit the boat when turned. A fresh coat of paint, new carpet on the bunks, and rewiring the lights will complete the trailer upgrade.

Although many of our technicians are handy with a wrench, one was an actual a mechanic before joining FISHBIO. He handles some of boat and truck maintenance when he has time, as shown below–everything from oil changes to replacing gaskets. We’re thankful our technicians have a diversity of skills to keep our shop and fabrication lab running smoothly.

Categories : Fabrication

Tags : boat maintenance

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Ant snacks

Attractive acne?

Don’t dump that fish

Going custom

A small obstacle

Secrets of the Mekong

Water or beer?

Purple sea

Surviving the south Delta

Double duty

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