Site selection

De Almeida, Fabiane F., Ector, Luc, Silva, Edinaldo Santos & Wetzel, Carlos E., 2020, Gomphonema frequentiformis (Metzeltin & Krammer) comb. nov. (Bacillariophyta): ecology and taxonomy of a Neotropical diatom, Phytotaxa 439 (3), pp. 265-275 : 266-267

Site selection

The left bank near the city of Manaus was divided into three areas representing a certain degree of potential anthropogenic impact: 1) low anthropic influence area (LAI), upstream of the Manaus city; 2) intermediate anthropic influence area (IAI), already close to urban area but without strongly polluted tributaries and 3) high anthropogenic influence area (HAI) in front of the city of Manaus ( Figure 1 ).

The LAI is located between the Lake Tatu (3º03’10.77 ‘’S and 60º17’45.30’’W) and east of Tarumã-Mirim stream (3º01’56.20’’S and 60º17’32.95’’W). Four sampling (S1 to S4) stations are distributed in this reach that has approximately 20 km. The IAA also has four sampling stations and is bounded on the west by the of Tarumã-Mirim stream (3º01’56.20 ‘’S and 60º17’32.95’’W) and east by Tarumã-Açu stream (3º02’42.65’’S and 60 06’55.36’’W) (sites S5 to S8) and is approximately 10 km long. Finally the HAI is located between the Tarumã-Açu (3º02’42.65’’S and 60°06’55.36’’W) and the Ceasa docks (3º09’44.59’’S and 59 58’44.65’’W). This reach (of approximately 20 km) has also four sampling stations (S9 to S12) and is characterized by having two major organically polluted sites (S9 and S10). All sampling stations are located before the confluence with the Solimões River which after their confluence, becomes the so-called Amazon River downstram of Manaus.

Figures

FIGURE 1. A) Distribution of Gomphonema frequentiformis comb. nov. in South America; B) Sampling sites located on the left bank of the Negro River, in the vicinity of Manaus city, Brazilian Amazon; C) Distribution of Gomphonema frequentiformis in the sampling stations 1 to 12 at Manaus (AM, Brazil).