Rivière· 83 segments

Merrimack River

Crosses 5 administrative regions : Essex, Hillsborough, Merrimack, Middlesex, Rockingham

rivière

Total length

198km

Max discharge

261,7m³/s

Max Strahler

Segments matched

River geography5 admin regions · 0 communes

Parent watershed

hybas-7080466110184 km²

5 administrative regions crossed (GADM L2)

Merrimack
New Hampshire · United States
77.9 km
in this dpt
Essex
Massachusetts · United States
67.5 km
in this dpt
Hillsborough
New Hampshire · United States
62.2 km
in this dpt
Middlesex
Massachusetts · United States
19.3 km
in this dpt
Rockingham
New Hampshire · United States
0.2 km
in this dpt

30 intersecting protected areas

North Shore Ocean Sanctuary
IUCN V
Marine Protected Area
Parker River National Wildlife Refuge
IUCN IV
Marine Protected Area
Parker River
IUCN IV
National Wildlife Refuge
Essex County Greenbelt Association 1
IUCN V
Greenbelt
Manchester Cedar Swamp
IUCN V
Private Conservation Land
New Hampshire Department of Transportation
IUCN VI
Mitigation
Upper Merrimack Oxbow
IUCN V
Conservation Easement
Weir Hill
IUCN V
Reservation
Lower Beaver Brook Land
IUCN V
Local Conservation Area

21 more protected areassorted by area

Unknown
IUCN V
Park
Carr Island
IUCN V
Sanctuary
Booth Property
IUCN V
Local Conservation Area
Van Loan
IUCN V
Preserve
Fife Trust#2, Clarence C.
IUCN Not Assigned
Conservation Easement
Town of Pelham Land
IUCN V
Local Conservation Area
Ritchie CR
IUCN Not Assigned
Conservation Easement
Emmons
IUCN V
PCL
New Hampshire Technical Institute / Concord -
IUCN III
Island Reserve
Brox CR
IUCN Not Assigned
Conservation Easement
Barker Farm CR
IUCN Not Assigned
Conservation Easement
Amesbury Road
IUCN V
Conservation Area
Ram Island
IUCN V
Sanctuary
Edgewood Farm CR
IUCN Not Assigned
Conservation Easement
Chase Farm
IUCN Not Assigned
Conservation Easement
Rolling Ridge CR
IUCN Not Assigned
Conservation Easement
Half-Mile Hill Summit
IUCN V
Conservation Area
Upper Artichoke Reservoir
IUCN V
Conservation Area
Benedictine
IUCN V
Park
Ram Island State Wildlife Sanctuary - Salisbury Wildlife Sanctuary
IUCN VI
Marine Protected Area
Woodland
IUCN Not Assigned
Park

1 page = 1 named river (aggregation of 83 HydroRIVERS v10 segments). Spatial join cached after first hit.

Species present

423 distinct species · 4 241 observations

Source: GBIF Occurrence snapshot 2026-05-01.

Ecological tissue

Sample of 42 species (selected proportionally per kingdom among those with at least one documented interaction here) to keep the graph readable. Hover for details, click to explore the full ecosystem of a species.

ℹ️ The territory contains many more species than displayed and all their documented interactions: the graph is intentionally the structural skeleton (top-N species by composite local score, edges filtered by Serrano 2009 disparity filter α=0.2).

RègnesAnimalPlanteChampignonBacterie

RelationsPredationParasitismeSymbiosePollinisation

StatutEn dangerVulnérableProtégéeEndémique

RègnesAnimalPlanteChampignonBacterie

RelationsPredationParasitismeSymbiosePollinisation

StatutEn dangerVulnérableProtégéeEndémique

Indicateurs du tissu écologique

Tissu écologique de Merrimack River : 27 espèces reliées par 88 interactions GloBI sur 5 types (connectance 10.2%, filtre Serrano α=0.2). 15 bulles taxonomiques (cascade genre/famille GloBI, ≥3 espèces).

Espèces affichées

Interactions affichées

Connectance

0.102

Patrimoniales

Plus dense que (national)0 %(top 100%)

Comparaison sur la connectance du réseau local complet vs distribution nationale (toutes les communes françaises).

Hydrology (HydroRIVERS v10)