Marine Species Richness by Zone

import matplotlib.pyplot as plt
import seaborn as sns
import pandas as pd
import numpy as np

np.random.seed(2222)

zones = ['Epipelagic', 'Mesopelagic', 'Bathypelagic', 'Abyssal']
data = []
for zone in zones:
    n = 40
    temperature = np.random.uniform(2, 25, n)
    diversity_base = {'Epipelagic': 3.5, 'Mesopelagic': 2.2, 'Bathypelagic': 1.5, 'Abyssal': 0.8}
    diversity = diversity_base[zone] * np.log(temperature + 5) + np.random.normal(0, 0.4, n)
    for t, d in zip(temperature, diversity):
        data.append({'Temperature (°C)': t, 'Shannon Index': d, 'Depth Zone': zone})

df = pd.DataFrame(data)

sns.set_style("whitegrid", {
    'axes.facecolor': '#ffffff',
    'figure.facecolor': '#ffffff',
    'grid.color': '#eeeeee'
})

palette = ['#27D3F5', '#276CF5', '#4927F5', '#5314E6']

g = sns.lmplot(
    data=df,
    x='Temperature (°C)',
    y='Shannon Index',
    hue='Depth Zone',
    col='Depth Zone',
    col_wrap=2,
    height=3.5,
    aspect=1.2,
    palette=palette,
    scatter_kws={'alpha': 0.7, 's': 55, 'edgecolor': 'white', 'linewidths': 0.6},
    line_kws={'linewidth': 2.5},
    ci=95
)

g.fig.set_facecolor('#ffffff')
for ax in g.axes.flat:
    ax.set_facecolor('#ffffff')
    for spine in ax.spines.values():
        spine.set_color('#dddddd')

g.fig.suptitle('Marine Biodiversity Gradients', fontsize=14, fontweight='bold', color='#1a1a1a', y=1.02)
plt.tight_layout()
plt.show()