March 1 "Whenever the alewives return, spring after spring, I ask them where they have been..." - John Hay, The Run. We can expect the first scouts to arrive around the spring equinox, March 19th this year, as they are ever punctual. Until then, we inspect our passage in the Slough Pond woods and see that it is ready for their arrival. The fallen tree limbs have been removed and the water is deep and flowing, sending its scent out to the alewives who call it their home pond. We will follow the footsteps of our dear friend and mentor John Hay along the paths of Stony Brook, the fish ladder, and the shores of the natal ponds, as another migratory season begins.
March 8-10 The water level in the channel is high and flowing, overflowing its banks in some areas, in fact. It is possible the culvert pipe is clogged with debris which might the cause of some buildup. There is a good flow of water over the sandbag weir. The gauge at the landing has gone from 6.25" on February 29th to 7.25" on March 8th, with a record high of 7.75" on March 10th. The level is much higher than it was last year at this time. The gauge was not installed until March 31, 2023 when it read 6" but measurements at our house, approximately 300 yards from the landing, and in the channel itself, with a tape measure recorded lower levels last March at this time. So that is good news. "Running it out hard" has apparently begun at the Stony Brook fish ladder so we hope it won't draw down too much from our pond. It is a balancing act, drawing enough water so the accumulated pond levels over the winter won't create too powerful a force of water for the fish to navigate- which sometimes seems apparent- just enough to keep a good balance. It is the science of hydrology we depend on the Alewife Committee for.
In other news the AmeriCorps crew- who helped out at the Slough Pond passage last October 31 and December 1st- have been busy at other runs, in Eastham and Dennis among others, for spring cleanup, although there are not scheduled to return here. Let's hope the good work they did in the fall for us holds up. We are very grateful for their service.
And finally, I did not receive notice (as we usually do) of the Alewife Committee public meeting (video link provided) on Thursday, March 7th, otherwise I would have attended and alerted others. I have been lobbying for the meeting for several weeks so that was a disappointment, however, sometimes it is better to be an observer rather than a participant. There were many things stated I would have taken issue with, so I will here.
After all the hard work we did last year to gather useful data of the '23 migratory year at the passage, it was disheartening to hear the season so minimized at Slough Pond and our collected data ignored. I had hoped we would be building on the progress we made last year, after all that work, and listening to these comments made me feel we were back a square one; that we had never actually left square one. Nevertheless, it was good and proper that a spring public meeting was called and that it is on the public record, although some points need clarification to keep the record accurate. Please read below if you are interested. In the meantime, as a new migratory season has begun, our work continues and we look forward to greeting the alewives returning home to Slough Pond.
Also of note, the Town of Brewster has announced they are seeking one or two alternate herring wardens- read more here.
The repeated use of the word "ditch" to refer to the passageway, which, now that there is a temporary sandbag weir installed might very well qualify for the word "fishway" (which for all intents and purposes it is and has been for at least 75, possibly 150 years*), always sounds dismissive, if not derogatory. Although there is no historical data that the Slough Pond passageway was an irrigation ditch for cranberry farming, this is widely accepted. According to Cranberry Harvest, A History of Cranberry Growing in MA (Joseph D. Thomas, Ed., 1990), of the 102 taxed properties in Brewster in 1860, 42 were cranberry farms. These small family bogs were abandoned in the 1950's. There are some old bogs in proximity to Slough which could support this original use. Significantly, there are several active runs in abandoned bogs across Southeast MA, including Barnstable County, and our neighboring Towns of Harwich and Dennis, which manage them. By this calculation, the Slough passageway may have operated as a migratory run for herring for 164 years, in tandem with the ebb and flow of water into the wetland bog. No one knows when the now deteriorated culvert pipe was installed. On the subject of history, it should be noted that Dana Condit, Brewster's Head Warden for 40 years (who passed in 2000), never used the term ditch but referred to the passage as a herring run and he never sought to close it.
It was not just "a few herring" that used the migratory passage in April to return to Slough Pond, as stated; runs also occurred in May and June and the passage with thick with schools of hundreds. Many more weeks would have been operable in the passage for them if it had been cleared in the fall of '22 and spring of '23; only a minimal amount of clearing was allowed, after much insistence, but no digging, per order of the Head Warden.
Otters and raccoons "slaughtered" the stranded herring in the passage? As a citizen mentioned last year there is more predation in 10 minutes at the ladder than all season at the passage. Slaughter is hardly the right word for wildlife who are sustained by the spring migration, as humans once were as well, and tribal members still are. There is always predation at every run across the Cape, this passageway is no different. I saw evidence of only a handful of herring who had been eaten; whereas the warden's bucket that was installed to block the culvert trapped 12 adult herring, causing their death. If the passage had been deepened with fall or spring maintenance, the adequate water levels present, and enhanced with regular spring rainfall, would have allowed migration quite well, without interruption, and the adult herring would not have been as vulnerable to predation on the accumulated sandy shoals.
Not just "a few" juveniles ("brit" a little-used, archaic term for fry was used) were spawned in the pond but thousands, as well-documented at this site, and they were able to depart from September through December with the able-bodied help of AmeriCorps, help we advocated for through the fall. While it is accurate to say that the passageway dries up in the summer this is typical in wetlands, here and elsewhere, and the Slough Pond channel is never entirely dry. One could think of the water flow in spring as typical of flooded vernal pools and the new life they support. It is also practical that the fry remain in their natal ponds to gain strength through the summer before heading out to sea, so it could be thought of as beneficial.
The nets... "we will still explore the nets" according to the Head Warden. He stated he had undertaken research on them and decided to wait for the expertise of the DMF rather than install them himself. The Town's "Stream Management Plan" of '23 includes the addition, requested by Chris Miller, NRD, of the use of "temporary" nets or screening to block off the passage, without having to go through approval of the Conservation Commission or Division of Marine Fisheries. It is not hard to imagine that any temporary use, due to the hard work of installing them and high cost, would lead to it becoming permanent very easily. This would clearly need the approval of the DMF and CC, never mind citizenry. (I have added link outlining the research on netting/fish screens in Resources. This is NOT to be undertaken lightly by anyone, especially inexperienced, due to the deleterious effect it has on the fish, habitat, and other wildlife.)
The water level in the ponds is NOT lower than it was last year, as noted above.
There was some discussion on exploring the degraded Elbow Pond connection and its viability, though not on exploring the blocked Pine Pond connector. There was a brief mention of the ($1.2 million) restoration work at the ladder scheduled for the fall. The engineer's design plan for the work refers to the five headwater ponds of the Stony Brook Watershed that the restoration will assist. The watershed was once fed by seven headwater ponds (Pine, Elbow, Slough, Canoe, Upper & Lower Mills, and Walker's) all with migratory routes; all require different management than that at the fish ladder, but are no less part of the job of the wardens. We have lost Canoe and Pine, Elbow and Slough are under advisement, and if lost would leave three headwater ponds, two of which are compromised with toxic cyanobacteria blooms annually.
I do not take issue with the stated concern for water levels and the welfare of the herring, although this is better served by proper maintenance. Their appraisal of the two- year "River Herring Habitat and Nursery Assessment Study," which will be underway this month under the DMF, will help with their future decisions. The AC will respect the study period and wait for its data. It is significant that this is now on the public record. We know it is the opinion of the Head Warden that the passageway to Slough Pond should be closed, so we hope the study will provide data that will convince him/them that it is a critical habitat and nursery deserving of restoration. Warden Gary Kaser mentioned that Seymour Pond in Harwich could serve as a restoration model for Slough. He also brought up research on juveniles successfully overwintering in ponds if they can't get out; however, survival of thousands, is doubtful.
The Select Board liaison Kari Hoffmann, in attendance (along with Chris Miller, NRD, and Kim Crocker-Pearson, NRAC) asked the committee to vote on accepting an alternate member which they did. Interested parties should apply ASAP (link to application) to be interviewed by the SB which will appoint one person for a 1-3 year term. This idea has been floated for the past year and we are happy to see it coming to pass, though two alternates are allowed and it would be preferable to expand the actually committee with two wardens, but hopefully that is in the future. They have a lot of critical environmental decisions to make. (Kari is retiring from the Select Board and therefore as liaison to the AC in May. She has championed the idea of alternate wardens as well as the collaborative service of AmeriCorps, which she mentioned.)
There was a quorum of two wardens, Doug Erickson and Gary Kaser, for the meeting, the third warden, William LeMaitre, being in Florida. A member of the Mill Sites Committee, Scott Leonhardt, though not introduced, was seated at the table and as he is not a member of the Alewife Committee should have been asked to step down. It gave the impression he had some official capacity, which he did not, though I have been given to understand he was confused about the nature of the meeting. Doug, William, and Scott are on the Mill Sites Committee (of seven members) which is distinct from the Alewife Committee (of three members), although there is some overlap in grounds maintenance and water diversion.
March 12 Water is flowing consistently well over the sandbag weir at the mouth of Slough, less strongly along the passageway, coming to a standstill farther down, then rushing heavily after the culvert. The level is still good except for the 100 yards past the mouth. This area is consistently problematic as it accumulates sand run off from the pond. The depth here is only about 4". If the heavy draw down continues at the fish ladder and there is little rain the sandbags will need some adjustment to manage the flow and rebuild the level before the herring arrive within the next 2-4 weeks. Some targeted digging out might be helpful as well. The gauge at the landing records 7.25" - down a half inch since the weekend.
March 13 The Cape Cod Ponds Network started their monitoring of Slough Pond this morning. Senior Pond Monitoring Technician John-Tyler (JT) Percy and colleague Emma began collecting data on stratification, among other issues effecting the pond. (Forgot to take a photo!) Their arrival was earlier than expected, but JT explained that rainfall is so variable in March it was good to get a baseline measurement. They will return to Slough Pond once a month to gather data. We are so pleased that Slough was chosen as a representative pond, among 50 others, for their three-year study. The Network is a partnership between APCC and the Cape Cod Commission. Read more here.
March 17
It shouldn't be long now before the returning alewives find their way back to Slough Pond. The first scouts arrived at the fish ladder this week, 9 herring were counted at first, up to 70 this morning. The fish counter was installed on Friday. A few scouts usually arrive around the solstice, so they are right on schedule but apparently the first wave of migration is underway early; they are running in other towns. The herring migrate in when the inland waters are warmer than offshore waters: Cape Cod Bay recorded 41°F, 48°F in the passage, 50°F in the pond. A little close for comfort. Herring are used to cold temperatures in the ocean waters but spawning, of delicate eggs and milt, requires a bit more warmth.
The DMF habitat and nursery study begins this week so it couldn't be better timed. Only 4 of the headwater ponds will be under review, according to the Chair of the Natural Resources Advisory Commission. The water level in the passageway is holding its high level, for the most part, except for about 200 feet down from the mouth of Slough, where it has become shallower. It might be too late now to make adjustments in the sandbags, for water management, if the herring are running early. The passageway should be sufficient as is but could use some judicious digging in the days ahead. The gauge is down to 6.5".
March 19 The counter at the fish ladder on this first day of spring has counted 144 fish since its installation on Friday. I am not sure this is a reliable number as the early fish, especially, usually males, tend to come and go, testing the water, resting in the pools after their inland journey, and awaiting the females. The counter, in other words, may count the same fish more than once. We hope the issues the counter had last June have been resolved, as, from what I have heard, fish were being hurt by overcrowding, leading the wardens to take it out early.
The stream is flowing fiercely and at the top of the ladder the drop looked rather precipitous. As my friend John Hay has written in the chapter entitled The Imperfect Ladder, in his book The Run, "...managers of a good fishway must be constantly on the alert for new conditions... A marked increase or decrease in the volume of water, especially as it is reflected at the head of the fish ladder... may create a barrier instead of an aid." I don't usually post about the ladder at Stony Brook since my focus is on the Slough Pond passage. I have made an exception today since it is the Spring Equinox and the herring are running. I was hoping to catch sight of them. It will be two or three weeks before they arrive in Slough Pond if this year follows last year's timetable. The early fish tend to do their business quickly and it is the later arrivals that make their way farther upstream and linger a while. Sadly, there was nary a fin nor shadow of a herring in the water today when I was there, though mid-afternoon on a cloudy cool day is not the best time for observations..
March 21 Correction- 3/22: the Town did not remove the sandbags and it is a mystery at present who did. They will be returned to their original position and the public should take note. Proper water flow in the passageway is critical at this time. I was surprised to see that the sandbag weir has been dismantled at the passageway into Slough Pond. Not sure when this happened, perhaps yesterday or today. It does seem poorly timed. We know that the warden has been drawing down the upstream water very heavily at the fish ladder for the past couple of weeks- "running it out hard" - as he stated on March 7. I noted the other day that the current is quite strong down at the ladder and the lip looked precariously high for the fish to pass into Lower Mill Pond.
At our gauge here on Slough Pond, we lost another inch in the past four days: the pond level read 5.5" today, from a high of 7.75" just 10 days ago. (Effected by rainfall, water table, and draw down.) Last spring it took 3-4 weeks after the herrings' arrival at the ladder before they got all the way up to Slough; which means, there are a couple of weeks to work with here, water level wise. I measured a depth of 3.5" in the shallow areas of the passage closest to the pond entrance, the area that should be dug down, as I mentioned earlier, due to sand accumulation and leaf litter. The migrating adults need at least 5."
Removing the sandbags now will definitely decrease- not increase- the water level. Why were they were removed at this critical time? On the 17th I wrote that "it might be too late" to adjust them now. I did not envision the adjustment being their removal, rather, piling them to build up water in passageway by holding the pond water back. I must admit, I have been concerned about the sandbags since their employment in December for just this reason.
Meanwhile, the gauge measures a new record high, hovering just over 8.5" today, so we have gained a good 3" of rain since the 21st. Looking back over the month, the gauge read 7.25 on 3/8, 7.75 on 3/10, 6.5" on 3/17. and 5.5" on 3/21.