This document discusses regulations and survey techniques for freshwater mussels in Texas. It notes that 52 mussel species are found in Texas, with 1 federally endangered and 15 state-threatened. Surveys are required if a project may impact mussel habitat and listed mussels cannot be disturbed without permission. Surveys involve identifying mussel presence through timed or area searches and any listed mussels found are recovered and relocated. Data on location, counts, measurements and distributions are collected. Proper decontamination of equipment is required after surveys to prevent spread of invasive species to other waterways.
3. Protection Status in Texas
52 Species
โข 1 Federally-Endangered
โข 15 State-Threatened
โข 6 Candidates for Federal Listing
โข โListedโ โ Threatened or Endangered
4. When am I affected?
Impacts to Stream, River, or Reservoir
Bottom
โข Native Mussels
oCanโt disturb any threatened or
endangered species without permission
โข Canโt Transport Zebra Mussels
5. # of TPWD Threatened Mussel Species
Yes
Survey
(Approved by
TPWD)
Are Listed
Mussels
Present?
12. Timing
โข Seasonal Timing
oTPWD: March to October
oUSFWS: Late-April to November
โข Why?
โข Reduce Burrowing
โข Protect from Freezing
โข Lower Flows
19. โข Location
โข Number of each species
โข Measurements of specimens
โข Species richness
โข Catch per unit of effort
โข Distribution/densities
โข Photo documentation
Data Collection/Analysis
21. Post-Survey Requirements
โข Debrief SCUBA/Survey Team
โข Decontamination
o Per 31 TAC 57.112, regarding provisions to prevent spread of
exotic plants and animals (i.e., Hydrilla, Zebra Mussels)
o At site: Remove mud, plants, other debris from all vehicles,
boots, buckets, mesh bags, dive equipment, etc.
o Wash all equipment/vehicles with warm soapy water (~110ยฐF)
to kill larval stages
o Ensure drains lead to a WWTP, not directly into a waterway
o Allow all equipment/vehicles to thoroughly dry for at least 24
hrs before use at a second (uncontaminated) site
22. THANK YOU!
4009 Banister Lane, Suite 300
Austin, Texas 78704
512/329-0031
www.amaterra.com
10431 Morado Circle, Suite 300
Austin, Texas 78759
512/617-3164
www.freese.com
Victor Palma Dave Buzan
Editor's Notes
Title Slide
Purpose of first slide is to make sure everyone knows what we are talking about when we discuss mussels. We will tell them something like mussels have two shells, are filter feeders, live on the bottom with limited ability to move, and have larvae that parasitize fish. I suspect many of them have heard of zebra mussels. I think we need to give them a little explanation about zebra mussels and how they differ from native mussels.
The January 2010 decision by the TPWD commission set the stage for the regulatory environment we are in now. The fact that mussels live on the bottom and may never be seen led to them being largely ignored and understood by many people working on Texas freshwaters.
Iโve tried to design the following slides from the perspective if I was water district or river authority manager. I would want to know when something I might do may cause me to take action to protect mussels.
Are listed mussels possibly present in the county where the work will be done, if yes, TPWD will probably request a survey of mussels in the area to be disturbed. Counties that are white are not expected to have any listed mussels. The darkest red counties in east Texas may have up to 14 species of listed mussels.
If the survey finds mussels, TPWD will probably require an ARRP be submitted along with an application for a permit to introduce shellfish to state waters.
The Aquatic Resource Relocation Plan will need to be implemented by someone with a TPWD scientific collecting permit and it requires 30 day advance notice to TPWD
This is a mussel that was taken from a site on the Mississippi River where construction occurred in 1999. It was recovered in the area to which it was relocated 15 years later. This is evidence relocation works.
Once the ARR is complete, a report is due to TPWD within 30 days of completion
TPWD is authorized to seek civil restitution for each mussel killed.
This site was located in Robertson County about 320-30 minutes north of College Station. The survey was conducted because the existing bridge, which was deemed obsolete was being demolished and a new, wider bridge was to be built in its place. In the meantime, a temporary low water crossing was to be installed adjacent to the existing bridge. It would be used during the construction phase of the new bridge, and removed upon completion of the new bridge.
Before beginning any project like this, there are a number of things to consider. One is the time of year. Regulatory agencies prefer sampling to occur in the warmer months. This is because this is when mussels are most likely to be active and exposed (rather than burrowed deep in the sediment). Also, any exposed wet, fleshy parts of live mussels are less likely to be frozen. And, warmer months tend to have less flow/turbidity in the rivers. This survey was performed in mid-September.
For this particular project -- Time was of the essence โ as we had only two days to complete field work. TxDOT was dealing with a number of factors at this site ranging from abnormally high rainfall and subsequent flooding, to obtaining permits. So that by the time we were contracted to perform this survey, we had one week to prepare and two days to complete field work before construction crews were scheduled to begin demolition of the bridge and construction of the low water crossing. In fact โ bulldozers were already in action preparing the bank for the low water crossing by the time we left the water. A tighter schedule means more people, longer days, etc. to get the job done.
The primary consideration, of course, is Safety. Safety always comes first. As such, another consideration is to be aware of what hazards may be in the project area. Pre-survey, the Team will discuss the potential hazards in the area to be assessed, and how to deal with them during a survey or recovery. Surveys are not recommended when flows are greater than 2kts.
Surveys generally have one of two goals. It should be noted that Recovery and relocation may come without initial presence/absence survey if mussels are already known to be in a certain area, habitat, or watershed. That is what occurred at this site. TPWD knew mussels were found in the general watershed, although not at this specific site. As such, they permitted the project for recovery and relocation without a site specific presence or absence survey. So the goal of this project was to search and collect all live mussels in 100% of the survey area (ROW plus buffer zone), which was approximately 50 ft wide and 106 ft long. The mussels were then relocated upstream.
In Texas, almost all surveys are timed searches or area searches. Timed surveys are those where you sample a given area for a specified amount of time. Areal surveys are
A quick word about sampling in various water depths. For areas less than an armโs length in depth, hand grubbing (using your hand to dig 1-2โ into the substrate) is done. This may be accompanied with visual means using with a mask and snorkel, unless water clarity is too poor. According to USFWS protocols, such surveys should include inspections of all habitats (not just suitable habitats) within a survey area. If a previous survey was performed two or more years prior, a new survey is often recommended. In the Little Brazos River, this method was employed along the shorelines, where possible.
For areas greater than an armโs length in depth, SCUBA diving equipment should be used. In the Little Brazos River, the average water depth was about 5 feet. As such, SCUBA was used throughout most of the survey area. As can be seen here: If SCUBA is necessary โ it will always require a three-person team at a minimum. Safety always comes first โ so Divers should always use the buddy system โ that is two divers working in tandem, and one additional โready-to-goโ diver at the surface to support and assist the others as needed. Due to the accelerated schedule requirements, along with the need for SCUBA divers, the overall field team was comprised of five people: two active dives collecting specimens, a third support diver, and two biologists to identify and record required data. Additionally, the biologists helped sample shallow areas, as well as relocate the live mussels.
Examples of data collected during a survey includes items such as these. Note that โLocationโ can be both general โ or very specific,: Things such as Sample Area number, right bank, left bank, mid-channel, GPS coordinates. During this project we collected 480 live mussels representing 10 species, including two specimens of a state-listed species.
Once all data was collected,, the mussels were relocated upstream of the project area in a similar habitat (depth, velocity, substrate) โ as close-by as possible. โ in this case about 200 ft upstream. Such relocation criteria are outlined in the TPWD permit. Often selection of relocation site is made on the day of the survey to ensure similar habitat is found. Relocated mussels are hand placed, posterior end up, into the substrate.