by Dr. Sarah Treanor Bois, PhD
Director of Research & Conservation at the Linda Loring Nature Foundation
Summer on Nantucket is coming to an end. Usually at this time of year I try to hold on to summer. Phenologically, September is still part of the growing season, and it’s peak time for many of our wildflowers. That’s what I usually say. This year, however, is a bit different. We’re starting to see fall colors in August (!), plants going dormant earlier than usual, and some things withering before our eyes—more typical late fall activity.
What’s going on? We’re seeing and feeling the impact of our sustained drought.
We first discussed the drought on-island back in June, when the Level 1 drought was first declared. Nantucket County, including Nantucket main island, Tuckernuck, and Muskeget, has now been in a Level 1 drought since June of this year. Technically it is a “low level drought,” but it has been sustained for two months, so the effects on our habits are more pronounced. Interestingly, our sister island of Martha’s Vineyard is at normal conditions and has been for some time, while the Cape Cod region is still under Level 2 or “significant drought” conditions.
What does that mean for Nantucket?
Drought is a lack of cumulative conditions over time. Not only is the vegetation dry and crispy, but when we look at the data, we see well below normal rainfall. That, coupled with higher-than-normal summer temperatures, have led to the drought declaration.
From a practical and human stand point, it has meant water use restrictions and limitations for those on Town water. After months of drought conditions, it can mean depleted water supplies. Groundwater, freshwater wetlands, and ponds are significantly lower than normal. We can restrict water use like lawn watering and shorter showers, but what about our open space? How are our ecosystems experiencing these conditions?
At the Linda Loring Nature Foundation (LLNF), we record precipitation as part of two national programs: CoCoRaHS (the Collaborative Rain Hail and Snow Network) and we serve as a COOP Station for NOAA (National Oceanic and Atmospheric Administration). You can see a summary of our CoCoRaHS data at dex.cocorahs.org/stations/MA-NT-1/precip-summary. For this past summer, June was only at 23% of the 30-year norm, July at 31%, and August 35%. We will see what September brings, but much of the impact has already been felt by our vegetation.
What you might see when going on a walk in open space is bright fall colors. But it’s still summer…yes, the huckleberry, low-bush blueberry, and poison ivy have all started to go into premature dormancy—first turning red then brown. Similarly, many of our fall asters and goldenrods have bolted and turned brown: withered. It seems like many of these plants may not flower this season, instead deciding to conserve valuable resources. Our native species growing in sandy soils are used to limited water resources, but continued drought stress can inhibit photosynthesis which can lead to stunted plant growth or lower reproduction. One year of this kind of stress might not have a great effect on overall populations, but if this trend continues, we could see some deleterious effects on plant populations. Stressed plants are also weakened and, thus, are more susceptible to disease and opportunistic pests.
Drought can also lead to more soil erosion because the lack of water stresses plants, reducing vegetative cover and weakening the soil’s ability to resist wind and water. Dry soils can be eroded through wind. When soils are so dry, they can have a more difficult time absorbing water when it does fall. We need sustained precipitation to fully moisturize the soil. Another effect of the drought and heat combination is the increased wildfire risk. Crispy plants on the landscape are fuel just waiting for a match—these make it easier for fires to ignite and spread. Similar state-wide conditions last fall led to a significant increase in wildfires, including a 1,200% spike in October 2024 compared to previous years, as noted by Mass.gov. Because of this, residents are urged to take precautions such as conserving water, maintaining property to create defensible space, and being cautious with any potential spark from equipment or outdoor activities. It might not seem like a danger when having a bonfire on the beach in front of the ocean, but if a spark ignites a dune field, it can carry well inland.
Our wetlands are also feeling the effect. When ponds and wetlands are drawn down, it also concentrates the remaining water which can become stagnant. Stagnant water deteriorates water quality. This summer has also had record high temperatures. Warm, stagnant water is a breeding ground for algal blooms leading to multiple harmful algal blooms (HABs) this summer as reported by the Town of Nantucket and collaborating organizations (nantucket-ma.civilspace.io/en/projects/ harmful-algal-blooms-monitoring-program).
But it’s not all doom and gloom. The reduced water levels have opened up one unique habitat that is typically under water. Pond draw-down has enabled our coastal plain pond-shore habitat to showcase its seed bank. The coastal plain pond-shore is a globally rare, fragile habitat characterized by unique herbaceous plants that thrive on sandy, acidic, and groundwater-fed ponds whose water levels fluctuate seasonally, revealing exposed pond-shores in late summer. These ephemeral shorelines are critical for a high concentration of state and globally rare plants and animals. The Slender Marsh Pink (Sabatia campanulata) is one such plant that is listed as Endangered in the Commonwealth and visible in decent numbers this year during draw-down. We celebrate the ephemeral species having their day, but moving forward, water conservation will be the key.
So what to do?
- Adhere to watering restrictions laid out by Nantucket Town and the state
- Conserve indoor water use voluntarily, even if on well water
- Be fire-safe in the out of doors
- Plant drought-resistant and native species
Longer-term droughts will need additional considerations, but this is a good place to start. Droughts have always been a part of natural climate cycles; however, human driven climate change exacerbates their severity. Rising temperatures increase evaporative demand, which means the atmosphere pulls more moisture from water bodies, soil, and plants. This phenomenon transforms moderate droughts into severe ones. Recent studies have shown that warming trends make droughts last longer, cover larger areas, and cause more significant environmental harm. So we should expect more drought conditions and the accompanying water restrictions in the future.
