There and Back Again: A Blueback's Tale
If you've been an active reader of our blog or have kept up with our research and restoration work, you may be aware that river herring refers to two species: alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis). This is done mostly because they are so similar in appearance - and hence, very difficult to tell apart - and because they have similar life history characteristics. Yet differences do exist. Alewife are typically more abundant in the northern part of their range that includes the entire Atlantic coast; while within spawning rivers, blueback herring typically travel further upstream to spawn. Morphologically, alewife have slightly larger eyes and a grey-green dorsal side (back), while blueback herring have a more blue-green back (hence the name I'm assuming). Yet the most foolproof way to tell them apart is by the color of their peritoneum, the membrane that surrounds their abdominal cavity. Alewife have a pale white peritoneum, while blueback herring have a black peritoneum. Unfortunately, the only way to see this membrane is to cut them open, which is why we only do this to the few river herring we find dead in our nets each year.
Since we started our monitoring in 2014, all herring checked in this way have been alewife, including both adults and juveniles/young-of-year. And a blueback herring hasn't been recorded in Wreck Pond since 2006, when two were caught by Capt. Al Modjeski as part of a prior study. That is, until today.
As we approached our net this morning, we discovered a headless herring lying on the pond bank. After processing the living fish in our net (which included white perch, gizzard shad, American eels, white suckers, brown bullhead, pumpkinseeds, bluegills, and 11 river herring) we cut open the headless herring expecting to see a pale peritoneum confirming it as an alewife. However, we were shocked and excited to see otherwise. A bold, black peritoneum signified this fish as a blueback herring, something we haven't seen in here in 15 years. It appears, blueback herring are back in Wreck Pond.
Now to the nature of its headless appearance. The ragged look of the wound suggests the alewife was preyed upon by another organism. There has been a sighting of a river otter in Wreck Pond this year, and we observed river otter tracks on the beach last summer. Otters are known to eat fish head first, and accounts exist from fishermen from early in the last century of their nets being raided by otters and having an entire catch headless as a result. Perhaps our headless fellow suffered the same fate. We don't know, but we are excited to continue monitoring this year and see what else we can learn.
And we're back! After an extended hiatus due to the covid pandemic, our spring fish sampling has officially restarted. While this year may be a little different (limited volunteers, social distancing, masks), we are excited to be back out catching fish. And catch we did. Over the past few days, we caught several white perch, white suckers, and stripped killifish, as well as an American eel, two golden shiners, a common carp, and a bluegill. I am also happy to report that we caught our first alewife of the season: a medium-sized female with lots of energy. Make sure to stay tuned for more updates throughout the season.
Hello everyone and Happy New Year!!! The Wreck Pond team would like to wish everyone a very happy and healthy New Year. We all are looking forward to a new start and all that is to come in 2021.
The team continued working through the Fall and into Winter monitoring for any unique movements in the colder months. We pulled the seine net twice, once in November and once in December. Novembers pull did not yield anything unique or unexpected, however, Decembers pull was quite the contrary.
As we shuffled through the silver sides, we came across two specimen that made us do a double-take. Here they are below:
When ever we catch something that could be a river herring, we get really excited. At first glance, we thought Fish 1 on the left could be an alewife, but after further investigation, it was determined Fish 1 was an Atlantic Menhaden. They were spotted running in the surf and this juvenile likely got pushed through the pipe into the pond.
Fish 2, however, was quite different. It didn't fully resemble the juvenile alewife we've caught previously, but certainly appeared to be in the herring family. It is potential this is a Blueback river herring, something we have not seen in years at the pond. It is not 100%, but the unique catches this winter are exciting, and have encouraged the team to continue winter pulls once per month throughout the 2021 winter season.
Aside from winter seining, the team was excited to see the completion of the Old Mill Dam Fish Ladder Project. The ladder itself was installed in late August, however, the rock diversion to help lead migrating herring to the base of ladder has not been installed. Well, as of December 22, the diversion is in and will be ready for the 2021 migration!
The team continues to push through and genuinely cannot wait to keep working hard to restore Wreck Pond. We have lots of exciting plans in 2021 and hope you continue on the journey with us.
Be well, stay safe, and healthy, and Happy New Year!
For more information on the Wreck Pond project, please visit www.littoralsociety.org for more information or contact Julie Schumacher, Habitat Restoration Technician: email@example.com
During these difficult times, the Wreck Pond team has made an effort to create virtual content of the work they do at Wreck Pond to continue engaging and involving the community. In response to these changing times, the team has created the 3 Part 'Restoring Wreck Pond' video series. These videos overview the Wreck Pond Restoration Project, the sampling that has been conducted, the Wreck Pond citizen science program, and now, the Old Mill Dam fish ladder. Each video is roughly 5-6 minutes. Below, you will find each of the 3 educational videos including the exciting bonus video overviewing the installation and completion of the Old Mill Dam Fish Ladder. We hope you enjoy !
Part 1: Restoring Wreck Pond - This Video overviews the Wreck Pond Restoration Project and the installation of the 600ft fish passage box culvert that was installed in 2016.
Part 2: Fish Sampling and Monitoring - This video overviews both the spring and fall fish sampling that has been conducted at Wreck Pond post-construction of the fish passage box culvert.
Part 3: Wreck Pond Citizen Science Monitoring Program - This video acts as a virtual training for the citizen science monitoring program.
BONUS VIDEO: Old Mill Dam Fish Ladder - This video documents the installation and completion of the Old Mill Dam Fish Ladder furthering migrating fish species access to spawning habitat within the Wreck Pond Brook watershed.
The American Littoral Society is thrilled to announce the installation and completion of the Old Mill Dam Fish Ladder ! It has been a long time in the making, but the Wreck Pond team is elated to share this exciting news of the continuation and ongoing effort to restore Wreck Pond.
Now, instead of Old Mill Dam acting as the furthest migration destination for Alewife and Blueback river herring, these fish now have the ability to navigate up the dam through the fish ladder and utilize roughly an additional mile of optimal spawning habitat. The American Littoral Society will add the Old Mill Dam fish ladder and newly accessible spawning habitat into its ongoing river herring monitoring surveys.
We've gone solar!
As many of you are aware, we use passive integrated transponder (PIT) tags to monitor the alewife that make their way into Wreck Pond each year to spawn. Tagged fish are tracked using antennas positioned throughout the pond and larger watershed. Each antenna is powered by 2-4 marine 12volt batteries. Because of the power demands of the antennas, these batteries need to be replaced each week. The old batteries are then charged to be reused the following week. At around 50lbs each, moving and swapping batteries is not easy feat. And the task becomes even more daunting when you have 6 or 7 antennas going!
This year, to alleviate some of that work, reduce our time in the field, and become more eco friendly, we incorporated solar panels into our antenna set up. The panels charge our batteries in the field while they are powering the antennas. This has extended the life of our charged batteries and allowed for fewer battery swaps.
While we cannot yet conduct our spring fish sampling, in the next week we will be restarting our PIT tagging antennas. To prevent contact, staff will be assigned individual antennas to monitor once a week. Hopefully, we will detect some repeat spawners, as each year we typically catch several alewife that were tagged the previous year and have returned to Wreck Pond once again to reproduce. Let's hope that trend continues! Stayed tuned for weekly updates on the PIT tagging results. Some underwater camera footage is in the works as well.
A PIT tagging computer.
An addition is coming to Old Mill Dam. Later this spring, we will be installing a fish ladder over the Old Mill Dam spillway. Our PIT tagging work has shown that, currently, alewife reach the bottom of the dam during their spring spawning runs. The installation of the ladder will make available almost a mile of extra, good spawning habitat. The ladder will be an Alaskan steeppass design (see image below). After construction, we plan to install additional PIT tagging antennas on the fish ladder to assess its utilization by alewife. We are currently waiting for permit approval from the NJDEP, and anticipate construction to start end of March or April. This project is the result of collaboration with the United States Fish and Wildlife Service. Additionally, Wall Township, The Mill Lakeside Manor, and Atlantic Lifts, Dock & Bulkhead have been instrumental in getting the project to this stage. Stay tuned for more information as we get closer to the anticipated construction time period.