Smithsonian miscellaneous collections

In the narrow western portion, a limited amount of exchange occurs with the waters of New York Harbor. Riley and others (1956 and 1959) have studied the physical and chemical oceanography as well as some of the flora and fauna of L.I.S. Phosphate does not appear to be a major limiting factor for phytoplankton growth in the central basin.

Lighting, water column stability and nutrient supply were suggested to explain these differences. Zooplankton.- The seasonal cycle for zooplankton showed a maximum in late spring and late summer, with a minimum occurring in midwinter. This suggests that sometimes most of the organic matter appears as detritus or as organisms that contain very little chlorophyll.

Most of the stations are located in north-south traverses numbered 1 to 5 from west-to-east (fig. 1). A few centimeters of water above the sediment-water interface and the top centimeter of the core were placed in a vial with neutralized formalin at the time of collection.

LABORATORY WORK

In order to be accurately located, the seasonal samples in between were given different location data, the seasonal samples in between were given different station numbers.

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS J sample was washed in a bank of sieves having openings of 125

SIGNIFICANCE OF A FORAMINIFERAL SAMPLE

A sample is assumed to be representative of both the distribution and abundance of foraminifera at the sampling location (station) and of the total area represented by the sample. Phleger (1952) has indicated that in the Gulf of Maine, foraminiferal samples are representative of the total area represented by a sample because the distribution of species is not random, has localized centers or high points, and decreases in an orderly manner from these highlights. Due to the stability of the percent distribution of species in deeper areas, Walton concluded that his sampling grid provided an adequate representation of the distribution of the species.

Each member of the sample pair was taken within minutes of the other, using the same method and at the same location, as conditions permitted. Although only the most frequent species were used in the chi-square calculation, in some sample pairs the expected frequency in a given cell was less than two. In the living populations of sample pairs and 108-108', two of the three widespread species had an expected frequency of less than two, so the chi-square was not calculated in these cases.

In general, we can conclude that in the living population, the proportions of the investigated species are homogeneous in sample pairs from the coastal area. We can conclude that in the entire population the proportions of the three studied species are homogeneous in all these sample pairs from the coastal area.

10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 Statistical Significance of Numbers of Individuals

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS II Statistical Significance of Numbers of Individuals

The offshore areas are more homogeneous and the number of individuals at a station can be more reliably estimated than in the

DISTRIBUTION OF THE FORAMINIFERA

I FORAMINIFERA IN MANY BUZAS SIX ISLAND IISstatistical significance of numbers of individuals. lobata, and Nonionella atlantica are represented only by empty tests. The species Eggerella advena, Elphidiiimincertum {E. clavatum of this study), E. subarticum {E. pauciloculum of this study), Eponides frigidus var. The double study of this area is instructive because it shows that caution should be used when considering the significance of the number.

On the other hand, the more abundant species are, as one would hope, abundant in both cases. On average, stations in L.I.S. fewer species and greater dominance by a single species than the more open ocean waters of Block Island Sound. The increase of species to the east is probably due to two factors, namely migration to L.I.S.

Traverse 3 was sampled at seven different times, and the three abundant species show the same pattern over and over again. It should be emphasized that the same pattern shown in Figure 2 was observed every time 3 was tried.

14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS 15

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS I7

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS 21 Size of the Living Population

24 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 The percentage limits placed on the zones reflects the pattern v^hich is

26 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 to the proximity of sampling times, it was decided to compare the

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 27 in August 1961 had 417 and 681 living individuals respectively

28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49

The areal distribution of Buccella frigida as a percentage of the total population is shown in figure 15. The areal distribution of Eggerella advena as a percentage of the total population is shown in figure 16. Nearshore areas, except for the north shore of Long Island east of longitude geographic 73°.

An area of 200-500 individuals per sample is located at the northern end of traverses 2 and 3 and extends eastward to almost the entire area of traverse 4. The western part of the central area contains a large area of 90-200 individuals per sample that decreases in size in the east. In general, the areas where the largest number of empty tests occur are also the areas with max.

36 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, I49 ZONATION OF THE TOTAL POPULATION

SEASONAL SAMPLES

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 39 of the ten stations in this zone on the traverse of March 1962 were

40 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49

The abundance of living Foraminifera in October and June correlates in a general way with the zooplankton and phytoplankton

THE FORAMINIFERA IN RELATION TO THE SEDIMENTS

44 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 dormant during the winter and therefore would not offer any

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 45 Several different approaches were used in attempting to draw a

IN FORAMINIFERA IN LONG ISLAND SOUND BUZAS 47Microscopic examination of the fraction >125fi showed the most Microscopic examination of the fraction >125fi showed that the most abundant constituent was quartz. In the silty sand and the clayey silt, the most abundant component in the 125-62/n fraction is elliptical faecal pellets. Since clay-sized particles tend to bind organic matter, the clay content of the sediment is often an important factor in controlling the distribution and abundance of benthonic organisms.

He was also able to relate the abundance of different animal organisms to the size of the sediment particles. For example, at station 19 the sediment is gravelly sand composed of 29 percent gravel, 59 percent sand, 8 percent silt, and 4 percent clay; the number of living foraminifera is. At station 14, the sediment is sand, consisting of 13 percent gravel, 82 percent sand, 3 percent silt, and 2 percent clay; The number of living foraminifera is 441.

Station 116 is a silty sand composed of 0.5 percent gravel, 70 percent sand, 14 percent silt, and 15 percent clay; the number of living foraminifera is 47. Station 119 is a clay loam composed of 10 percent sand, 44 percent silt, and 45 percent clay; the number of living Foraminifera is 40. These examples and a close examination of the data show that particle size has no effect on the number of living Foraminiferain L.I.S.

48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 Similarly, the distribution of species cannot be related to particle

At station 10 both the living and dead populations are increasing, but the living population is increasing at a greater rate. The maximum is the result of an increase in the living population combined with a decrease in the dead population at these stations. At stations 8 and 9 the dead population increases while the live population remains constant, resulting in lower L/T values.

The L/T frequency distribution of all species shows that at stations 3 to 8 the distribution is controlled by the L/T ratio for E. If the L/T ratio of all species is an accurate indicator of the relative rate of sedimentation, then the L/T ratios of the constituent species should show same pattern. In passage 3, the L/T ratios of the three abundant species give a different interpretation of the relative sedimentation rate.

SIGNIFICANCE OF ENVIRONMENTAL FACTORS

Riley (1959) has shown that the western end of the Sound is usually about 3-5%o cooler than the eastern end. The increase in foraminiferal species in the east is most likely due to the more oceanic conditions found there and the proximity of the open ocean from which sound migration can occur. At some stations a strong odor of HgS arose from the black mud in the cores, and at some of these stations the living population was abundant.

McCrone et al (1961) showed that pH is usually approximately neutral, while Eh is negative. I FORAMINIFERA ON LONG ISLAND SOUND BUZAS 53Conover (1956, p. 69) stated that the concentration of phyto- Conover (1956, p. 69) stated that the concentration of phyto-plankton under a unit sea area is usually greater offshore. Although planktonic diatoms have been shown to be an important food source for Elphidium crispum, Myers (1943) stated that this foraminifer feeds mainly on benthic unicellular plants.

Riley (personal communication) indicated that calculations from the Secchi disk indicate that the lower limit of the benthic microflora in the L.I.S. None of the species in this study are restricted to depths less than 11 m, but Elphidium clavatum is most abundant at depths less than 10 m. Bradshaw (1955) found that one species of foraminifera he reared would feed only on live Nitzchia diatoms, while another species would accept both live and dead flagellates.

Lee et al. (1961) found that an algal flora of eight species of feathery diatoms and three blue-green algae was the best support for the species they cultured. Myers (1943, p. 442) suggested that below the photic zone bacterial growth on faecal pellets might provide an important food source for foraminifera. Obviously, the food requirements of Foraminifera are complex and vary from species to species.

Because temperature, salinity, nitrate, phosphate, oxygen, pH, Eh, particle size of the sediment and concentration of phytoplankton apparently do not control the observed depth zonation, I suggest that the foraminiferal species in L.I.S.

PALEOECOLOGIC IMPLICATIONS

I have shown that the distribution of the living and the total population approaches each other. Therefore, a study of the total population would generally provide an accurate account of foraminiferal distribution in the L.I.S. The low number of species per sample and the dominance of a single species suggests a limited marine environment.

Even if the relatively fragile tests of Eggerella advena were to be destroyed, offshore and near-shore environments could. In short, provided the sediments could be correlated and the future paleontologist knew as much about the Foraminifera as we do now, the general environmental characteristics of the fossilized sediments of L.I.S. be worked out.

SYSTEMATIC CATALOG OF SPECIES

The increase in numbers of species to the east would indicate the approach of more oceanic conditions in that direction.

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 55 Living and dead individuals belonging to this species occur with

I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 55Living and dead individuals belonging to this species occur.

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS S7 Family TROCHAMMINIDAE

White, opaque individuals often have several distinct umbilical ridges that are sometimes fused by the addition of shell material so that only irregular fissures appear in the umbilical region. Furthermore, when the CaCOa from the test was dissolved, all samples examined showed a thick brown organic inner coating not found in any other species in this area. White, opaque individuals with retral processes and irregular sutures and/or umbonal bosses have been and continue to be referred to E by several workers.

My views are similar to hers, but I think it is best to refer to this species, as E. Parker (1952a) observed the same conditions in his study of the Gulf of Maine fauna. Nevertheless, the two species are morphologically very similar, and further investigation of the expected range of variation is desirable.

62 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 Family ROTALIIDAE

GENERAL SUMMARY

64 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49

The expected frequency (e) of the species in a sample is calculated by multiplying the row sum of the species by the column sum of the sample and dividing by the total sum of both samples.

SAMPLE PAIR 10-10'

SAMPLE PAIR 14-14'

SAMPLE PAIR 24-24'

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 67

SAMPLE PAIR 102-102' Total Population

SAMPLE PAIR 106-106'

SA .MPLE PAIR 108-108' Total Population

SAMPLE PAIR 125-125

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 7Z

T6 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49

NO. I FORAMINIFERA IN LONG ISLAND SOUND — BUZAS

84 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I49 Table 11

NO. I FORAMINIFERA IN LONG ISLAND SOUND BUZAS 85 Table 11 — (continued)

CUSHMAN, J. A

EXPLANATION OF PLATES

SEE EXPUANATION OF PLATES AT END OF TEXT.)

SEE EXPLANATION OF PLATES AT END OF TEXT.)